CN113380278B - Optical disk reading method, reading device and optical disk reading and writing device based on nano photoetching - Google Patents

Abstract

The invention provides an optical disk reading method, an optical disk reading device and an optical disk reading and writing device based on nano photoetching. The technical scheme of the invention comprises the following steps: forming a white light source, and focusing and irradiating the white light source on an information recording point of a recording layer of the physical storage medium of the optical disk; collecting a measurement light signal; obtaining the depth information w of the continuous writing groove on the recording layer of the optical disc physical storage medium in advance _k And its corresponding digital storage information s _k Reflectance measurement spectral information ref _k The association relationship of (a); obtaining reflectance measurement spectral information ref from the measurement optical signal _k ' thereafter, the reflectance measurement spectrum information ref matched with the correlation is searched in the correlation _k Corresponding continuous writing groove depth information w _k Further, the continuous writing groove depth information w _k Digital storage information s of the corresponding information recording point _k Reading out, so as to effectively improve the reading speed and resolution capability of the optical disc information and greatly improve the storage density and storage dimension of the optical disc.

Description

Optical disc reading method, reading device and optical disc reading and writing device based on nano-lithography

This application is a divisional case of a Chinese invention patent application filed by the same applicant with an application date of 2018-11-20, an application number of 2018113839605, and an invention title of "A method for reading and writing optical discs based on nanolithography and a method for encoding and decoding writing control information" Apply.

technical field

The invention relates to the field of optical technology, in particular to a method for reading an optical disc based on nano-lithography, a reading device and an optical disc reading and writing device.

Background technique

With the development of technologies such as gene sequencing and brain activity reading, not only a large amount of data is generated, but also higher requirements are put forward for how to store the data effectively, stably and accurately. Based on the above-mentioned background, the optical disk storage technology has well adapted to the requirements of the times due to its advantages of energy saving, long storage life, good safety and easy processing. As for optical disc technology, the limitation of storage capacity seriously hinders the development of optical disc technology.

In order to increase the capacity of the optical disc, the traditional technical route is to reduce the size of the recording spot. With the successful development of short-wavelength laser diodes (GaN blue-green lasers), Blu-ray discs have gradually become the mainstream storage method in the optical disc market. In the early CD discs, the recording laser wavelength was 780nm, the numerical aperture was 0.45, the track pitch was 1.6μm, and the single-layer storage capacity was only 650MB; the later DVD discs had a recording laser wavelength of 650nm, the numerical aperture was 0.6, and the track pitch was 0.74 μm, the single-layer storage capacity is 4.7GB; while the current Blu-ray disc recording laser wavelength is 405nm, the numerical aperture is 0.85, the track pitch is 0.32μm, and the track pitch is only half of that of the red DVD disc (0.74μm). The storage capacity is as high as 25GB. At the same time, the Blu-ray disc uses different reflectivity to achieve multi-layer writing effect, realizing 12 layers of 300GB Blu-ray disc storage.

In order to further break through the limitation of optical disk storage capacity, researchers have also proposed some methods to increase storage capacity. In 2009, Gu Min's research team in Australia used the difference in the response of gold nanowires with different aspect ratios to laser light of different wavelengths and polarization directions to realize three-layer five-dimensional (and polarization) optical information storage within the thickness (Nature, 2009, 459 (7245):410-413). In 2011, the S.W Hell research team proposed a new microscopic technology RESOLFT (reversible saturated optical'fluorescence'transition between twostates) that can be used for super-resolution optical storage reading and writing, using the photocuring and photoswitching properties of green fluorescent protein (rsEGFP) , through the method of super-resolution writing and reading, a high-density optical storage experiment with a pitch of 250nm was realized (Nature, 2011, 478, 204-208). In 2012, Gu Min's research team in Australia combined the principles of photopolymerization and super-resolution stimulated radiation loss technology, and used the 1,5-bis(p-dimethylaminooctaneimide) cyclopentanone (BDCC) material system to achieve a 9nm The lithographic channel width is 52nm and the channel pitch is 52nm (Nature Communications, 2013, 4.6:2061). Using this photopolymerization lithography mechanism, the optical disc information can be written in high density. Accordingly, Gu Min's research team applied for an international patent (Appl. No: 15/039,368; PCT No: PCT/AU2013/001378).

Contents of the invention

The purpose of the present invention is to provide an optical disc reading method, a reading device and an optical disc reading and writing device based on nano-lithography, so as to increase the reading speed of the optical disc.

其中，/>

为所述信息记录点的第i个刻写沟槽的反射光场；E₀为未刻写沟槽的反射光场；m为所述信息记录点的数据存储位点的位数；“0”和“1”数码分别表示所述信息记录点的数据存储位点是否有刻写沟槽；n₁(λ)为所述光盘物理存储介质的记录层的折射率，其依赖于刻写光束的波长λ；Z_i为第i个刻写沟槽的深度信息，Z₀＝0表示未刻写的沟槽深度信息为0；l₀为所述记录层的厚度；

Δn＝n₁-n₀，n₀为空气的折射率；预先获得所述光盘物理存储介质的记录层上的连续刻写沟槽深度信息w_k及其对应的数字存储信息s_k、反射测量光谱信息ref_k的关联关系；在从所述测量光信号中得到反射测量光谱信息ref_k′后，在所述关联关系中查找与之匹配的反射测量光谱信息ref_k所对应的连续刻写沟槽深度信息w_k，进而将该连续刻写沟槽深度信息w_k对应的所述信息记录点的数字存储信息s_k读出。In order to achieve the above object and other related objects, the present invention provides a method for reading an optical disc based on nanolithography, comprising: forming a white light source, and focusing and irradiating it on an information recording point of the recording layer of the physical storage medium of the optical disc; collecting Measuring optical signal; the measuring optical signal includes the total reflected light field coherently superimposed by the reflected light fields of the writing grooves of the information recording point

where, />

Be the reflected light field of the i-th writing groove of the information recording point; E ₀ is the reflected light field of the unwritten groove; m is the number of bits of the data storage position of the information recording point; "0" and The numbers "1" respectively indicate whether there is a writing groove at the data storage point of the information recording point; n ₁ (λ) is the refractive index of the recording layer of the physical storage medium of the optical disc, which depends on the wavelength λ of the writing beam; Z _i is the depth information of the i-th written groove, Z ₀ =0 means that the depth information of the unwritten groove is 0; l ₀ is the thickness of the recording layer;

Δn=n ₁ -n ₀ , n ₀ is the refractive index of air; obtain in advance the continuously written groove depth information w _k on the recording layer of the optical disc physical storage medium and its corresponding digital storage information s _k , reflection measurement spectrum The association relationship of information ref _k ; after obtaining the reflection measurement spectrum information ref _k ' from the measurement optical signal, search for the corresponding continuous writing groove depth corresponding to the reflection measurement spectrum information ref _k in the association relationship information w _k , and then read out the digital storage information _sk of the information recording point corresponding to the continuously written groove depth information w _k .

In an embodiment of the present invention, the method further includes: focusing and irradiating a white light source on the next information recording point of the recording layer of the optical disc physical storage medium; according to the measurement optical signal of the next information recording point and the correlation The relationship is to obtain the digital storage information of the next information recording point until the digital storage information _sk of all information recording points is read out.

在获得经测量得到的一信息记录点的反射光谱信息ref_k′时，在所述关联关系中查找与之匹配的反射测量光谱信息ref_k所对应的连续刻写沟槽深度信息w_k，进而将该连续刻写沟槽深度信息w_k对应的数字存储信息s_k作为解码得到的所述信息记录点的数字存储信息。In order to achieve the above object and other related objects, the present invention provides a method for decoding lithographic information from the reflectance measurement spectrum, including: establishing in advance the continuous writing groove depth information w _k and its Corresponding relationship between digital storage information s _k and reflection measurement spectral information ref _k ; wherein, each reflection measurement spectral information ref _k constitutes a reflection measurement spectrum set

When obtaining the measured reflection spectrum information ref _k ′ of an information recording point, search for the corresponding continuously written groove depth information w _k corresponding to the reflection measurement spectrum information ref _k in the correlation relationship, and then write The digital storage information _sk corresponding to the continuous writing groove depth information w _k is used as the digital storage information of the information recording point obtained by decoding.

其中，

为所述信息记录点的第i个刻写沟槽的反射光场；E₀为未刻写沟槽的反射光场；m为所述信息记录点的数据存储位点的位数；“0”和“1”数码分别表示所述信息记录点的数据存储位点处是否有刻写沟槽；n₁(λ)为所述光盘物理存储介质的记录层的折射率，其依赖于刻写光束的波长λ；Z_i为第i个刻写沟槽的深度，Z₀＝0表示未刻写的沟槽深度信息为0；l₀为所述记录层的厚度；/>

Δn＝n₁-n₀，n₀为空气的折射率；处理模块，用于预先获得所述光盘物理存储介质的记录层上的连续沟槽刻写信息w_k及其对应的反射测量光谱信息ref_k的关联关系；在从所述测量光信号中得到反射测量光谱信息ref_k后，在所述关联关系中查找与之匹配的反射测量光谱信息ref_k所对应的连续刻写沟槽信息w_k，据以作为所述信息记录点的数字存储信息s_k读出。In order to achieve the above object and other related objects, the present invention provides a nano-lithography-based optical disc reading device, including: an optical path module, used to form a white light source, and focus and irradiate it on a recording layer of the physical storage medium of the optical disc. Information recording point; used to collect optical measurement signals; the measurement optical signal includes the total reflection light field coherently superimposed by the reflection light fields of the depth information writing grooves of the information recording point

in,

Be the reflected light field of the i-th writing groove of the information recording point; E ₀ is the reflected light field of the unwritten groove; m is the number of bits of the data storage position of the information recording point; "0" and The numbers "1" respectively indicate whether there is a writing groove at the data storage point of the information recording point; n ₁ (λ) is the refractive index of the recording layer of the physical storage medium of the optical disc, which depends on the wavelength λ of the writing beam ;Z _i is the depth of the i-th writing groove, Z ₀ =0 means that the depth information of the unwritten groove is 0; l ₀ is the thickness of the recording layer;/>

Δn=n ₁ -n ₀ , n ₀ is the refractive index of air; the processing module is used to obtain in advance the continuous groove writing information w _k on the recording layer of the physical storage medium of the optical disc and its corresponding reflection measurement spectral information ref The association relationship of _k ; after obtaining the reflection measurement spectrum information ref _k from the measurement optical signal, searching for the continuous writing groove information w _k corresponding to the reflection measurement spectrum information ref _k matching it in the association relationship, The digitally stored information _sk is read out as said information recording point.

In an embodiment of the present invention, the optical path module includes: a light source, a lens group, a high-magnification objective lens, a beam splitter, and a single lens; the processing module includes: a spectrometer; wherein, the light source is used to emit white light; the The lens group is used to collimate and expand the white light and converge it to the beam splitter; the beam splitter is used to split the received white light and emit it to the high-power objective lens; the high-power objective lens , used to focus the received white light on the surface of the physical storage medium of the optical disc to perform reflection measurement on its recording layer, and emit the collected measurement optical signal; the single lens is used to converge the measurement optical signal to The spectrometer; the spectrometer is used to process the received measuring light signal and decode data storage information therefrom.

In an embodiment of the present invention, the spectrometer includes: a grating spectrometer or a high-speed measurement spectrometer; the high-speed measurement spectrometer includes: an optical dispersion element, a narrowband integrated filter, and a linear array detector; wherein the optical dispersion element , for splitting the received measurement optical signal so that the reflection spectrum information is spatially expanded; the narrow-band integrated filter is used for obtaining the wavelength corresponding to the reflection spectrum information dispersed by the optical dispersion element Light: the linear array detector is used to detect the light intensity of the light of each wavelength obtained by the narrow-band integrated optical filter, so as to obtain reflection spectrum information.

In an embodiment of the present invention, the light source is a halogen lamp, a tungsten lamp, a xenon lamp, a white LED lamp, a band-pass filtered white light source, or an ultraviolet LED light source.

To achieve the above object and other related objects, the present invention provides an optical disc reading and writing device based on nano-lithography, including: the above-mentioned optical disc reading device based on nano-lithography.

In an embodiment of the present invention, the reading device further includes a third dichroic mirror, arranged between the lens group and the beam splitter of the reading device, for collimating and expanding the beam passing through the lens group The white light is reflected to the high-magnification objective lens; the beam splitter is used to split the measurement light signal emitted by the high-power objective lens; the single lens is used to converge the measurement light signal split by the beam splitter to the spectrometer.

As mentioned above, the optical disc reading method, reading device and optical disc reading and writing device based on nanolithography of the present invention have the following beneficial effects:

1. Realized the reading of nanometer-sized information recording points;

2. It has higher storage density and storage capacity, and faster reading speed;

3. The scalability is strong, and there is no need to make major improvements to the existing optical drive system.

Description of drawings

FIG. 1A is a schematic diagram showing the structure and writing principle of an optical disk physical storage medium in an embodiment of the present invention.

FIG. 1B is a schematic diagram showing the structure and writing principle of an optical disk physical storage medium in another embodiment of the present invention.

FIG. 1C is a schematic diagram showing the spectrum of the absorption modulation layer of the diarylethene material in an embodiment of the present invention.

FIG. 1D is a schematic diagram showing the influence of optical disc physical storage medium structure optimization on spectral resolution in an embodiment of the present invention.

FIG. 1E is a schematic structural diagram of an optical disk physical storage medium in another embodiment of the present invention.

FIG. 2A is a schematic flowchart of a method for writing an optical disc based on nanolithography in an embodiment of the present invention.

FIG. 2B is a schematic diagram showing the relationship between digital storage information s _k , continuous writing groove depth information w _k and reflectance measurement spectral information ref _k in an embodiment of the present invention.

FIG. 3A is a schematic flowchart of a method for reading an optical disc based on nanolithography in an embodiment of the present invention.

FIG. 3B is a schematic diagram showing the principle of reflectance spectrum measurement and reading in an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of an optical disc reading and writing device based on single-beam nanolithography in an embodiment of the present invention.

FIG. 5 is a schematic structural diagram of an optical disc read/write device based on dual-beam nanolithography in an embodiment of the present invention.

FIG. 6 is a schematic structural diagram of an optical disc read-only device based on nanolithography in another embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

It should be noted that the diagrams provided in the following embodiments are only schematically illustrating the basic ideas of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

first embodiment

As shown in Figure 1A, an optical disc physical storage medium is shown, and its structure includes:

1) protective layer 101, which enables the optical disc to withstand frequent use, fingerprints, scratches and dirt, thereby ensuring the storage quality and data security of the optical disc;

2) The recording layer 102 is used for writing and recording information. This layer is characterized by stable preservation and optical writing. The selected materials include SiO ₂ , GaF ₂ , MgF ₂ , plexiglass, photosensitive materials, etc., but not limited to these;

3) The reflective layer 103 is used to increase the spectral reflectance and facilitate the reflection measurement of spectral information. It adopts materials with high reflectivity, mainly including metal materials or multi-layer distributed Bragg reflector (DBR) materials, but not limited to these .

By using shorter wavelength writing laser beams (semiconductor lasers with 405 nm or shorter wavelength output, or 355 nm and 266 nm solid-state laser outputs, or 248 nm, 193 nm, and 157 nm output excimer lasers, etc.) and high numerical The focusing mode of the aperture objective lens obtains a compressed diffraction-limited focused spot 104, and the light beam acts on the recording layer to write digital information. Combining with the 2 ^m -bit digital information encoding method, taking m=3 as an example, different groove depths Z ₁ , Z ₂ , the continuous writing of Z ₃ , in which, the writing corresponding to (m) indicates that the digital "1" is stored in this place, otherwise, the digital "0" is stored, and the different (m) corresponds to the 2 ^m -bit digital information encoding method different digits; so far, the information storage at 107 is completed, and then move to the next fixed position according to 105, repeat the above process to complete the digital information storage; and so on, complete the whole process of digital information storage.

second embodiment

As shown in Figure 1B, a physical storage medium of an optical disc is shown, and its structure includes:

1) protective layer 201, which enables the optical disc to withstand frequent use, fingerprints, scratches and dirt, thereby ensuring the storage quality and data security of the optical disc;

2) Absorption modulation layer 202, the material of this layer has absorption modulation characteristics, and its absorption spectrum has the characteristics as shown in Figure 1C. Nitrogen-based materials, but not limited to these;

3) The recording layer 203 is used for writing and recording information. This layer is characterized by stable preservation and optical writing. The selected materials include SiO ₂ , GaF ₂ , MgF ₂ , plexiglass, photosensitive materials, etc., but not limited to these;

4) The reflective layer 204 is used to increase the spectral reflectance and facilitate the reflection measurement of spectral information. It adopts materials with high reflectivity, mainly including metal materials or multi-layer distributed Bragg reflector (DBR) materials, but not limited to these .

In another embodiment, further, a transition protection layer of less than 10 nm may be added between the absorption modulation layer 202 and the recording layer 203 as needed, so as to prevent the absorption modulation layer 202 from affecting the recording layer 203 . The material of the transition protective layer includes: PVA (polyvinyl alcohol), PMMA (polymethyl methacrylate) and the like.

Combined with the above-mentioned physical storage structure of the optical disc, the solid writing beam 205 and the hollow suppression beam 206 act on the absorption modulation layer 202 at the same time, and through the absorption modulation characteristic, the hollow suppression beam 206 suppresses the peripheral beams of the solid writing beam 205 from passing through the absorption modulation layer 202 , so that the writing spot size passing through the absorption modulation layer is further compressed, as shown in 207, the hollow suppression beam 208 suppresses the peripheral beam of the solid writing beam 209 through the absorption modulation layer 202, and the compressed beam 210 acts on the recording layer 203 for writing depth information grooves. Combined with the 2 ^m -bit digital information encoding method, taking m=3 as an example, the digital storage points (1), (2), and (3) at the fixed position 212 of the information recording point on the 203 are carried out with different groove depths Z ₁ , Z ₂ , Z ₃ continuous writing, in which, the writing corresponding to (m) means that the number "1" is stored at this place, otherwise, the number "0" is stored, and the different (m) corresponds to the 2 ^m -bit code At this point, the information recording at 212 is completed, and then move to the next fixed position according to 211, repeat the above process to complete the digital information storage; and so on, complete the whole process of digital information storage.

It should be noted that, for the optical disk physical storage media in the first embodiment and the second embodiment, the protective layer 101 and the protective layer 201 are not necessary, and in the absence of the protective layer 101 and the protective layer 201, other layers can also be used independently. implement.

third embodiment

Referring to Figure 1D, the resolution of the spectrum determines the number of bits of coded information. In order to increase the resolution of the reflection spectrum measurement, this embodiment is based on the first embodiment and the second embodiment, by combining the recording layer 102 with the reflective layer 103 or between the recording layer 203 and the reflective layer 204 by adding one or more intermediate layers, thereby providing a physical storage medium for an optical disc. In detail, its structure includes:

1) The recording layer 303 is used for writing and recording information. This layer is characterized by stable preservation and optical writing. The selected materials include SiO ₂ , GaF ₂ , MgF ₂ , plexiglass, photosensitive materials, etc., but not limited to these;

2) The middle layer 304 is a material with a high refractive index, the refractive index is greater than that of the material of the recording layer 303, and the spectral absorptivity is low. The material thickness of this layer is smaller than the measurement wavelength. The selected materials include Al ₂ O ₃ , Si ₃ N _4. Nb ₂ O ₅ , Ta ₂ O ₅ and TiO ₂ etc., but not limited to these;

3) The reflective layer 305 is used to increase the spectral reflectance and facilitate the reflection measurement of spectral information. It adopts materials with high reflectivity, mainly including metal materials or multi-layer distributed Bragg reflector (DBR) materials, but not limited to these .

FIG. 1D shows reflectance measurement spectrum information 306 and 307 corresponding to the physical optical storage medium without an intermediate layer and the optical storage physical medium with an intermediate layer added. Comparing 306 and 307, it can be clearly seen that the spectral resolution ability of the optical disc storage physical medium after adding the intermediate layer has been significantly improved:

(1) Compared with 306, 307 has a more obvious "peak position" movement;

(2) The intensity change of 307 is more severe, and the coding information can be distinguished in a smaller window, such as 360nm to 400nm, which provides the possibility to read spectral information by using a light source in the ultraviolet range;

(3) The difference in the peak shape of the corresponding reflection spectra between different digitally encoded information increases.

Therefore, by adding an intermediate layer or multiple intermediate layers, the spectral resolution can be greatly improved, thereby further improving the encoding dimension m of the writing control information to be introduced below, and greatly increasing the information storage capacity.

Fourth embodiment

Carrying over the structure described in the second embodiment, as shown in FIG. 1E , another optical disc physical storage medium is shown. The recording layer 402 of the optical disc physical storage medium has been completed on the second surface (see the plane in contact with 403 in the figure). The writing of photolithographic information is realized, and a reflective layer 401 is newly added on the first surface (see the plane in contact with 401 in the figure).

The formation method of the physical storage medium of the optical disc is as follows: after the recording layer 203 of the second embodiment is optically written, the absorption modulation layer 202 of the optical disc (if there is a transition layer) is cleaned by chemical methods such as ultrasonic waves, and after cleaning, the The recording layer 203 is reversed 180 degrees to form the recording layer 303 in which the second surface of the optical writing shown in FIG. 1D is down and the first surface is on the top. 403) in 1E are stacked, the first surface is newly plated with a reflective layer 401, and a dielectric cavity is formed between the reflective layer 401 and the reflective layer 403. The reflective layer 401 can be made of metal materials such as gold and silver, or multi-layer DBR materials. The reflective layer 401 is also a protective layer of the optical disc.

The dielectric cavity structure makes the lifetime of spectral information depend only on the lifetime of the recording layer, thereby realizing the permanent preservation of stored information. In addition, it also achieves a substantial increase in storage density and storage capacity.

fifth embodiment

The optical disk physical storage media introduced in the first embodiment to the fourth embodiment can all be regarded as a "single-sided" structure. This embodiment provides a "double-sided" optical disk physical storage medium, so as to achieve the effect of double-sided high-density information storage. The so-called "double-sided" structure can be regarded as a "back-to-back" arrangement of two "single-sided" structures sharing a reflective layer 103 or reflective layer 204 . In this embodiment, the reflective layer 103 in the first embodiment or the reflective layer 204 in the second embodiment is used as the base layer, and other layers are symmetrically arranged on the upper surface and the lower surface of the base layer. For example, taking the optical disk physical storage medium introduced in the first embodiment as an example, its structure extended to double sides is a protection layer, a recording layer, a reflection layer, a recording layer, and a protection layer from top to bottom.

Sixth embodiment

As shown in FIG. 2A, this embodiment provides a method for writing an optical disc based on nanolithography, which includes the following steps:

S21: Compressing the focal spot size of the solid writing beam.

The beam intensity of the solid writing beam conforms to the Gaussian intensity distribution, and visible, ultraviolet, and deep ultraviolet continuous lasers or pulsed lasers with wavelengths between visible light and ultraviolet light can be used. Specifically, compressing the focal spot size of the solid writing beam can be achieved by means 1 or 2:

Method 1: Form a solid writing beam and a hollow suppressing beam with different wavelengths respectively, the beam intensity of the hollow suppressing beam conforms to the annular intensity distribution and the central intensity tends to zero; make the focal plane of the solid writing beam and the hollow suppressing beam Spatially overlapped; the overlapped light beam is irradiated on the physical storage medium of the optical disc, and the hollow suppressing beam suppresses the peripheral spot of the solid writing beam, for example: the absorption modulation of the hollow suppressing beam irradiating on the physical storage medium of the optical disc Another example: under the action of the hollow suppression beam, the absorption modulation layer inhibits the peripheral light spot of the solid writing beam from passing through the absorption modulation layer, and another example: the solid writing of the method 1 or the method 2 The beam adopts a pulsed beam to realize a two-photon writing method, etc., so as to compress the focal spot size of the solid writing beam;

Method 2: reducing the wavelength of the solid writing beam and/or increasing the numerical aperture of the objective lens.

S22: Read the digital storage information to be stored in the optical disc as writing control information.

In detail, the writing control information includes sub-writing control information arranged in sequence. Each of the sub-writing control information is used to control the writing of an information recording point; the information recording point includes m data storage locations, and each of the sub-writing control information is composed of m-bit binary numbers, and each bit is binary The numbers "0" and "1" in the number are used to indicate whether to write the corresponding depth information groove at the corresponding data storage position.

Specifically, the encoding method for writing control information includes the following steps:

Step 1, using the number m of data storage points contained in each information recording point to be written as a power of 2 to determine the use of 2 ^m- ary numbers for encoding;

Step 2, using the m-bit binary digital storage information to be stored in the optical disc as the writing control information _sk of an information recording point to be written; The writing of the information groove corresponds to the "0" and "1" numbers assigned to each binary number in the group;

1≤k≤2^m，以作为总的刻写控制信息。Step 3. The writing control information of all the information recording points to be written forms a 2 ^m -bit digital information set

1≤k≤2 ^m , as the overall writing control information.

Optionally, different depth information is used to represent different digits for data storage at each of the data storage sites, that is, a variety of different depth information grooves are used at the same data storage site to represent different storage numbers, thereby improving data information storage. quantity. For example: at the same data storage location, 4 different depth information are used to represent and store the numbers "0", "1", "2", and "3" respectively, so as to increase the information capacity of the stored data.

Referring to Fig. 2B, for example, each information recording point now has 3 data storage points, so it needs to be coded by octal numbers; the digital storage information _sk of each 3-bit binary number is a group, as a piece of information to be written The writing control information of the recording point, and if the first data storage point of the writing information recording point needs to be written, the first binary number "1" in the group will be assigned, and if no writing is required, it will be assigned "0"Digital; if the second data storage point of the engraved information recording point needs to be engraved, then the second binary number "1" in the group is assigned, and if no engraving is required, it is assigned "0", and so on. In FIG. 2B, "001" represents the writing control information of the second information recording point to be written, and the first and second bits are "0" respectively, and the third bit is "1", indicating that the second bit to be written is "1". No writing is done at the first data storage point and the second data storage point of the writing information recording point, but a groove with a depth of Z ₃ needs to be written at the third data storage point.

S23: According to a group of m bits of writing control information in the writing control information, control the compressed focal spot to write corresponding information recording points on the recording layer of the optical disc physical storage medium.

Corresponding to the encoding method described in step S22, this step adopts a decoding method for writing control information during specific implementation, including the following steps:

Step 1. According to a group of m-bit binary numbers in the digital storage information, write the corresponding information recording point on the recording layer of the optical disc physical storage medium; wherein, judge whether to record the information at the information recording point according to the digital number of each binary number The corresponding depth information groove is written at the corresponding data storage point, and the continuous writing groove depth information w _k1 of the information recording point is formed after writing;

直至完成所有信息记录点的刻写，形成总的连续刻写沟槽深度信息/>

1≤k₁,k₂≤2^m。Step 2. After the writing of the information recording point is completed, the solid writing beam is moved to the next information recording point, and the solid writing beam is controlled according to the next set of m-bit binary numbers in the digital storage information. Groove writing, after writing, the continuous writing groove depth information of the information recording point is formed

Until the writing of all information recording points is completed, the total continuous writing groove depth information is formed />

1≤k ₁ , k ₂ ≤2 ^m .

Referring to FIG. 1A, taking m=3 as an example, three fixed positions (1), (2), and (3) at the information recording point 107 of the recording layer 102 are performed with different groove depths Z ₁ , Z ₂ , and Z ₃ , wherein whether to write or not depends on the content of the above-mentioned writing control code, if the number corresponding to (m) in the code is "1", then the groove depth Z _m is written at (m), if If the number corresponding to (m) is "0" in the code, it will not be written at (m). Of course, the meanings of "0" and "1" can also be exchanged in specific applications, that is, when the number is "0", it is written when it is "1", and it is not written when it is "1", which is not limited in the present invention. After the writing of the information recording point 107 is completed, move to the writing of the next information recording point according to 105 , and so on until the whole process of data recording is completed.

It is worth noting that information of different depths can also be used for data storage at the same data storage location, thereby increasing the amount of data information storage.

S24: After the writing of the information recording point is completed, move the compressed focal spot to the position of the next information recording point to be written, and control the writing according to the next group of m bits in the writing control information The information controls the compressed focal spots to write until the writing of digital storage information of all information recording points is completed.

Further, the optical disc writing method based on nanolithography in this embodiment further includes: controlling the writing depth of the groove at the data storage site on the recording layer by controlling the beam intensity and action time of the solid writing beam ; controlling the writing width of the groove at the data storage site on the recording layer by controlling the beam intensity and action time of the hollow writing beam.

It is worth noting that, through the optical disc writing method based on nanolithography in this embodiment, the size of the information recording point can be made not greater than 130nm, and the track pitch of the information recording point is not greater than 320nm, thereby improving the lithographic information writing speed. At the same time, the storage density and storage dimension of the optical disc are greatly improved.

Seventh embodiment

As shown in FIG. 3A, this embodiment provides a method for reading an optical disc based on nanolithography, including the following steps:

S31: Forming a white light source and focusing it on an information recording point of the recording layer of the optical disc physical storage medium.

S32: Collect and measure optical signals.

其中，/>

为所述信息记录点的第i个刻写沟槽的反射光场；E₀为未刻写沟槽的反射光场；m为所述信息记录点的数据存储位点的位数；“0”和“1”数码分别表示所述信息记录点的数据存储位点是否有刻写沟槽；n₁(λ)为所述光盘物理存储介质的记录层的折射率，其依赖于刻写光束的波长λ；Z_i为第i个刻写沟槽的深度信息，Z₀＝0表示未刻写的沟槽深度信息为0；l₀为所述记录层的厚度；

Δn＝n₁-n₀，n₀为空气的折射率。The measurement optical signal includes the total reflection light field formed by the coherent superposition of the reflection light fields of the writing grooves of the information recording point

where, />

Be the reflected light field of the i-th writing groove of the information recording point; E ₀ is the reflected light field of the unwritten groove; m is the number of bits of the data storage position of the information recording point; "0" and The numbers "1" respectively indicate whether there is a writing groove at the data storage point of the information recording point; n ₁ (λ) is the refractive index of the recording layer of the physical storage medium of the optical disc, which depends on the wavelength λ of the writing beam; Z _i is the depth information of the i-th written groove, Z ₀ =0 means that the depth information of the unwritten groove is 0; l ₀ is the thickness of the recording layer;

Δn=n ₁ -n ₀ , where n ₀ is the refractive index of air.

先经过记录层，折射率为n₁(λ)、厚度为l₀，再经过反射层，折射率为n₂(λ)、厚度为l₁，高倍物镜收集反射光谱信号即可获得反射光场，也即刻写方向与读取方向相反。由于，对于不同沟槽深度Z_i，对应的记录层厚度为(l₀-Z_i)，因此，某个信息记录点的第i个刻写沟槽的反射光场信号可表示为/>

其中，m为该信息记录点的数据存储位点的位数，“0”和“1”数码分别表示所述信息记录点的数据存储位点是否有刻写沟槽，n₁(λ)为记录层折射率，其依赖于波长λ，l₀为记录层厚度，Z_i为对应刻写沟槽深度(Z₀＝0)，/>

Δn＝n₁-n₀。这些不同的沟槽深度对应的反射光场构成了反射光谱测量的完备基E₀，E₁，E₂...E_m；测量光束衍射受限光斑内刻写了m位沟槽深度，其对应总的反射光场为各阶光场的相干叠加，即/>

反射光谱强度为

This step will be explained below in conjunction with FIG. 3B . In detail, using the optical disc physical storage medium of the first embodiment, the incident light field is

First pass through the recording layer with a refractive index of n ₁ (λ) and a thickness of l ₀ , and then pass through the reflective layer with a refractive index of n ₂ (λ) and a thickness of l ₁ , and collect the reflected spectral signals with a high-magnification objective lens to obtain the reflected light field , that is, the writing direction is opposite to the reading direction. Since, for different groove depths Z _i , the corresponding recording layer thickness is (l ₀ -Z _i ), therefore, the reflected optical field signal of the i-th writing groove of a certain information recording point can be expressed as />

Among them, m is the number of digits of the data storage position of the information recording point, and the numbers "0" and "1" respectively indicate whether the data storage position of the information recording point has a writing groove, and n ₁ (λ) is the record Layer refractive index, which depends on the wavelength λ, l ₀ is the thickness of the recording layer, Z _i is the depth of the corresponding writing groove (Z ₀ =0), />

Δn=n ₁ −n ₀ . The reflected light fields corresponding to these different groove depths constitute the complete bases E ₀ , E ₁ , E ₂ ... E _m for reflection spectrum measurement; m-bit groove depths are written in the diffraction-limited spot of the measurement beam, which corresponds to The total reflected light field is the coherent superposition of light fields of each order, that is, />

The reflection spectrum intensity is

S33: Obtain in advance the relationship between the continuously written groove depth information w _k on the recording layer of the optical disc physical storage medium, its corresponding digital storage information s _k , and the reflection measurement spectrum information ref _k .

As shown in Figure 2B, taking m=3 as an example, the corresponding writing control codes are "000" to "111", and grooves Z ₁ and Z of different depths are respectively performed at (1), (2) and (3). _2. For the information writing of Z ₃ , the writing results and reflection spectrum curves corresponding to each group of writing control codes are displayed below it. From the corresponding reflectance spectrum information in Figure 1D, it can be seen that within the spectral window of 340nm to 500nm, the corresponding reflectance spectra have large differences, including the movement of "peak", the change of intensity and the movement of "peak valley". wait.

S34: After obtaining the reflection measurement spectral information ref _k ′ from the measurement optical signal, search for the continuous writing groove depth information w _k corresponding to the matching reflection measurement spectral information ref _k in the association relationship, and then The digital storage information _sk of the information recording point corresponding to the continuously written groove depth information w _k is read out.

The data storage information can be decoded from the reflection spectrum in combination with the above steps S33-S34. According to the comparison between the measured reflection spectrum curve and the corresponding superimposed light field distribution, the writing information can be deciphered, and the m-bit digital storage information can be read at one time, which greatly speeds up the reading speed of the optical disc.

Further, the optical disc reading method based on nanolithography in this embodiment also includes: focusing and irradiating a white light source on the next information recording point of the recording layer of the physical storage medium of the optical disc; according to the measurement light of the next information recording point The data storage information of the next information recording point is obtained from the signal and the association relationship, until the data storage information of all information recording points is read out.

Eighth embodiment

As shown in FIG. 4 , an optical disc reading and writing device based on nanolithography is shown, and the reading and writing device can be divided into two parts: an optical disc writing device based on nanolithography and an optical disc reading device based on nanolithography. The optical disc writing device of this embodiment can be used to implement the writing of information on the optical disc physical storage medium of the first embodiment, and the principle of the optical disc writing method corresponds to that of the sixth embodiment; The principle of the optical disc reading method for reading digital storage information from the physical storage medium of the optical disc in the first embodiment corresponds to that of the seventh embodiment.

The optical disc writing device based on nanolithography in this embodiment includes: an optical path module and a control module, wherein the control module can use CPU, MCU, SOC and other control devices to execute steps S22-S24 introduced in the sixth embodiment , and by controlling the beam intensity and action time of the solid writing beam to control the writing groove depth at the data storage site on the recording layer; by controlling the beam intensity and action time of the hollow writing beam to control the The writing groove width at the data storage site on the recording layer.

When the optical path module uses the second method in the sixth embodiment to compress the focal spot size of the solid writing beam and irradiate it on the physical storage medium of the optical disc, the optical path module includes: a first laser 501, a first lens 502, A first filter 503 , a second lens 504 , a first dichroic mirror 505 , and a high-magnification objective lens 508 .

When working: the first laser 501 emits laser light with a first preset wavelength as a solid writing beam; the first lens 502, the first filter 503, and the second lens 504 are arranged in sequence along the optical path of the solid writing beam Wherein, the first lens 502 converges the solid writing beam, the filter 503 filters the solid writing beam converged by the first lens 502, and the second lens 504 collimates the solid writing beam filtered by the first filter 503 The beam is expanded and converged to the first dichroic mirror 505; the first dichroic mirror 505 is arranged at a certain angle with the second lens 504, and reflects the solid writing beam collimated and expanded by the second lens 504 to the high-magnification objective lens 508 ; The high-magnification objective lens 508 focuses the received solid writing beam and irradiates it on the surface of the optical disk physical storage medium 509 to write data storage information.

Preferably, the first laser 501 adopts a blue laser, an ultraviolet laser, a deep ultraviolet laser, or a high peak power laser with a wavelength range between visible light and ultraviolet light. Short-wavelength output, or 355 nm and 266 nm solid-state laser output, or 248 nm, 193 nm, and 157 nm output excimer laser, etc.) and the focusing mode of the high numerical aperture objective lens, to obtain a compressed diffraction-limited focus spot 104, the The light beam acts on the recording layer to perform information recording.

Preferably, the first filter element 503 uses a small hole or a single-mode fiber, for example: the writing beam exits from the laser 501, is focused by the lens 502, and selects the corresponding μm-level small hole 503 according to the focal length and NA of the lens 502 to process the light beam. For filtering, a single-mode fiber can also be selected instead of the small hole 503 .

The optical disc reading device based on nanolithography in this embodiment includes: an optical path module and a processing module, wherein the processing module can use a spectrometer 514 to execute steps S31-S34 described in the seventh embodiment. Types of spectrometer 514 include, but are not limited to, grating spectrometers or high-speed measurement spectrometers, high-speed measurement spectrometers, and the like.

The commonly used grating spectrometer adopts the method of mechanically rotating the grating, which is not suitable for high-speed reading and processing of data. In order to meet the requirements of optical disc reading on speed and sensitivity, the spectrometer 514 of this embodiment adopts a high-speed measuring spectrometer, which specifically includes: an optical dispersion element, a narrow-band integrated filter, and a linear array detector; wherein, the optical dispersion element is The received measurement optical signal is split to expand the reflection spectrum information in space; the narrowband integrated filter obtains the light of the wavelength corresponding to the reflection spectrum information dispersed by the optical dispersion element; the line array detects The detector detects the light intensity of the light of each wavelength obtained by the narrow-band integrated filter to obtain reflection spectrum information. Of course, in other specific applications, according to the actual spectral measurement requirements, the spectrometer can only use "optical dispersive element + linear array detector" or "integrated narrow-band filter + linear array detector" for fast spectral information measurement .

When the optical path module uses the second method in the sixth embodiment to compress the focal spot size of the solid writing beam and irradiate it on the physical storage medium of the optical disc, the optical path module includes: a light source 513, a lens group 512, and a high-magnification objective lens 508 , a beam splitter 507, and a single lens 511. In addition, in order to realize the combination with the writing device, the reading device further includes a third dichroic mirror 506, which is arranged between the lens group 512 and the beam splitting mirror 507.

During operation: the light source 513 emits white light; the lens group 512 collimates and expands the white light and reflects it to the third dichroic mirror 506, and then reaches the beam splitter 507; the beam splitter 507 splits the received white light and Emitted to the high-magnification objective lens 508; the high-magnification objective lens 508 focuses the received white light on the surface of the physical storage medium 509 of the optical disc to perform reflection measurement on its recording layer, and emits the collected measurement light signal; the beam splitter 507 pairs the high-magnification objective lens 508 The emitted measurement light signal is split; the single lens 511 converges the received measurement light signal to the spectrometer 514; the spectrometer 514 processes the received measurement light signal and decodes the data storage information therefrom.

Preferably, the light source is a halogen lamp, a tungsten lamp, a xenon lamp, a white LED lamp, a band-pass filtered white light source, or an ultraviolet LED light source. The band-pass filtered white light source enables the measurement spot to be compressed. The ultraviolet LED light source enables the measurement information recording point pitch and track pitch to be further improved.

In addition, the specific material of the recording layer can be selected according to the type of light source. For example, white light sources such as halogen lamps, tungsten lamps, xenon lamps, and white LED lamps can be selected. SiO ₂ and photosensitive materials can be selected as recording layer materials. The characteristics of such materials In order to have a high transmittance material in the visible light and ultraviolet band; and when using ultraviolet LED light source to improve the measurement information recording point spacing and track spacing, GaF ₂ , MgF ₂ etc. are selected as the recording layer material. The characteristics of this type of material are It has high transmittance in the ultraviolet and deep ultraviolet bands.

Ninth embodiment

As shown in FIG. 5 , a device for reading and writing an optical disc based on nanolithography is shown, and the device for reading and writing can be divided into two parts: an optical disc writing device based on nanolithography and an optical disc reading device based on nanolithography. The optical disc writing device of this embodiment is used to implement the writing of information on the optical disc physical storage medium of the second embodiment, the principle of the optical disc writing method corresponds to that of the sixth embodiment, and the optical disc reading device is used to realize the writing of information on the optical disc physical storage medium of the second embodiment. The principle of the method for reading information from the optical disk physical storage medium of the second embodiment corresponds to that of the seventh embodiment.

Different from the eighth embodiment, the optical path module of this embodiment adopts the first method in the sixth embodiment to compress the focal spot size of the solid writing beam and irradiate it on the optical disk physical storage medium. Therefore, the structure of the optical disk writing device of this embodiment can be regarded as adding: the second laser 601, the third lens 603, the second filter 605, the fourth lens 607, the hollow beam A generating element 609 and a second dichroic mirror 610 . Since the structure and working principle of the optical disc reading device of this embodiment are the same as those of the reading device shown in FIG. 3A , the details will not be repeated here.

When working: the second laser 601 emits laser light with a second preset wavelength; the third lens 603, the second filter element 605, the fourth lens 607, and the hollow beam generator 609 are along the optical path of the laser light with the second preset wavelength Arranged in sequence; wherein, the third lens 603 condenses the laser light of the second preset wavelength, the second filter 605 filters the laser light of the second preset wavelength condensed by the third lens 603, and the fourth lens 607 filters the laser light of the second preset wavelength condensed by the third lens 603. The laser beam of the second preset wavelength filtered by the second filter element 605 is collimated and expanded, and converged to the hollow beam generator 609, and the hollow beam generator 609 generates a hollow suppression beam according to the received laser beam of the second preset wavelength, and It emits to the second dichroic mirror 610; the second dichroic mirror 610 is arranged at a certain angle with the hollow beam generating member 609 and arranged parallel to the first dichroic mirror 611, and reflects the hollow suppression beam to the high-magnification objective lens 614; The high-magnification objective lens 614 focuses the solid writing beam to form a solid spot 616 with a size of "diffraction limit" and the hollow beam 617 of the hollow suppressing beam in space, and irradiates both on the surface of the physical storage medium 615 of the optical disc at the same time , to write data storage information; wherein, the solid light spot 616 is used for writing data storage information, and the hollow light beam 617 is used to prevent the peripheral light spot of the solid light spot 616 from passing through the absorption modulation layer of the optical disk physical storage medium 815 .

The above-mentioned realization of making the solid spot 616 and the hollow beam 617 coincide in space can be as follows: taking the hollow beam 617 as a reference, adjusting the divergence of the beam 616 by adjusting the front and rear positions of the lens 608, and simultaneously adjusting the dichroic mirror 611 to adjust the beam 616 The incident angle makes the solid light spot 616 and the hollow light beam 617 overlap in space, and acts on the physical storage medium structure 615 of the optical disc at the same time, so as to perform a data storage information writing process 618 on the recording layer.

Preferably, the light intensity of the laser with the first predetermined wavelength conforms to a Gaussian intensity distribution; the light intensity of the laser with the second predetermined wavelength conforms to a circular intensity distribution and the center intensity tends to zero. The writing beam can be blue light or ultraviolet short-wavelength continuous laser, or a high-peak-power pulsed laser from visible to ultraviolet can be selected according to the two-photon absorption characteristics of the material of the recording layer, so as to realize smaller-sized two-photon double-beam nano-information writing.

Preferably, the second filter 605 uses a small hole or a single-mode fiber, specifically: the writing beam exits from the laser 602, is focused by the lens 604, and the corresponding μm-level small hole 606 is selected according to the focal length and NA of the lens 604. For filtering, a single-mode optical fiber can also be selected to replace the small hole 606; the suppressed beam is emitted from the laser 601, focused by the lens 603, and the corresponding μm-level small hole 605 is selected according to the focal length and NA of the lens 603 to filter the light beam. A single mode fiber replaces the aperture 605.

Preferably, the hollow beam generator 609 adopts a vortex phase plate or a spatial light modulator to generate laser beams whose phases are distributed from 0 to π.

Tenth embodiment

As shown in FIG. 6 , it is an optical disc read-only device based on nanolithography, which is used to read the information of the optical disc physical storage medium such as the first embodiment or the second embodiment. The reading device based on nanolithography in this embodiment includes: a light source 701 , a lens group 702 , a high-magnification objective lens 704 , a beam splitter 703 , a single lens 707 , and a spectrometer 708 .

When working: the light source 701 emits white light; the lens group 702 collimates and expands the white light and converges it to the beam splitter 703; the beam splitter 703 splits the received white light and emits it to the high-power objective lens 704; the high-power objective lens 704 will receive The white light focused on the surface of the physical storage medium 705 of the optical disc to measure the reflection of its recording layer, and emit the collected measurement optical signal; the single lens 707 converges the measurement optical signal to the spectrometer 708; the spectrometer 708 processes the received Optical signals are measured and data storage information is decoded from them.

Since the optical disc reading method based on nanolithography performed by the optical disc read-only device in this embodiment has the same principle as that in the seventh embodiment, it will not be described again.

The optical disk read-only device of this embodiment can realize fast measurement and reading of signals, and the optical path is simple and stable. The spectrometer 708 obtains spectral information quickly by using an optical dispersion element and a narrow-band filter combined with a linear array detector, and Carry out signal processing to meet the practical requirements of fast data processing when reading CDs, and is suitable for high-speed reading of CD information.

In summary, the method for reading and writing optical discs based on nanolithography and the encoding and decoding method for writing control information of the present invention have the following beneficial technical effects:

1. Compared with the existing Blu-ray disc storage method, when m=0, the disc writing method of the nanolithographic information of the present invention is similar to the existing Blu-ray disc storage technology, but the present invention can realize smaller-sized information recording point, so that the size of the recorded information recording point and the track pitch can be equal to or smaller than or much smaller than the 130nm recording point and the 320nm track pitch of the existing Blu-ray; and when m≥1, the present invention effectively improves the storage density and storage dimension. Therefore, this method has higher storage capacity, faster reading speed, and stronger scalability;

2. The optical disc writing method based on nanolithography of the present invention increases the information storage density by reducing the spot size of the writing beam, and improves the information storage dimension by using different groove depths to represent different digits of digital information, thereby greatly improving Improve the storage density and storage capacity of optical disc information storage;

3. Utilizing the optical disc writing method based on nanolithography of the present invention for data storage, compared with the existing Blu-ray discs that use material refractive index changes for data storage, it has higher stability and is more suitable for long-term preservation of information;

4. Utilize the absorption modulation characteristics of the material to compress the focused spot of the writing beam, and precisely control the etching depth and etching width by controlling the intensity and action time of the writing beam and suppressing beam, and realize the nano-sized nano-lithography information writing process ;

5. The reflection spectrum measurement method can realize fast reading of stored information. At the same time, due to the white light spectrum reading method used in the data reading process, the data can be read under the positioning accuracy requirements of the existing optical drive, without the need for existing The optical drive system has been greatly improved;

6. By increasing the middle layer of high-refractive index material to improve the reflection spectrum difference and spectral reading resolution, the optical disc structure can be optimized according to specific practical requirements, which can further increase the storage capacity of the optical disc;

7. Propose a new physical storage structure of the media cavity of the optical disc, further improve the information writing density and spectral reading efficiency, and improve the life of the optical disc and the ability to resist scratches and dust;

8. The high-speed measurement spectrometer adopts optical dispersive elements and narrow-band filters, combined with the form of linear array detectors, can quickly obtain spectral information, and apply it to the reading of optical disc information, which greatly improves the reading rate of optical discs.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (7)

1. A method for reading an optical disc based on nanolithography, characterized in that it comprises: Form a white light source and focus it on an information recording point of the recording layer of the optical disc physical storage medium. The groove writing depth at the data storage site on the recording layer is controlled by the beam intensity and action time of the solid writing beam , the writing width of the groove at the data storage site on the recording layer is controlled by the beam intensity and action time of the hollow writing beam; Collecting measurement light signals; the measurement light signals include the total reflection light field formed by the coherent superimposition of the reflection light fields of the respective writing grooves of the information recording point

where, />

Be the reflected light field of the i-th writing groove of the information recording point; E ₀ is the reflected light field of the unwritten groove; m is the number of bits of the data storage position of the information recording point; "0" and The numbers "1" respectively indicate whether there is a writing groove at the data storage point of the information recording point; n ₁ (λ) is the refractive index of the recording layer of the physical storage medium of the optical disc, which depends on the wavelength λ of the writing beam; Z _i is the depth information of the i-th written groove, Z ₀ =0 means that the depth information of the unwritten groove is 0; l ₀ is the thickness of the recording layer;

Δn=n ₁ -n ₀ , n ₀ is the refractive index of air, different depth information is used to represent different bits for data storage at each data storage site, that is, multiple different depth information grooves are used at the same data storage site The slots respectively represent different storage numbers; Obtaining in advance the relationship between the continuously written groove depth information w _k on the recording layer of the optical disc physical storage medium and its corresponding digital storage information _sk and reflectance measurement spectral information ref _k ; After obtaining the reflection measurement spectral information ref _k ′ from the measurement optical signal, search for the continuous writing groove depth information w _k corresponding to the matching reflection measurement spectral information ref _k in the association relationship, and then use the The digital storage information s _k of the information recording point corresponding to the continuous writing of the groove depth information w _k is read out. 2. The method according to claim 1, further comprising: Focusing and irradiating the white light source on the next information recording point of the recording layer of the physical storage medium of the optical disc; The digital storage information of the next information recording point is obtained according to the measurement optical signal of the next information recording point and the association relationship, until the digital storage information of all information recording points is read out. 3. A method for decoding lithography information from reflectance measurement spectra, comprising: Pre-establish the relationship between the continuously written groove depth information w _k on the recording layer of the optical disc physical storage medium and its corresponding digital storage information s _k , and reflection measurement spectral information ref _k ; wherein, each reflection measurement spectral information ref _k constitutes a reflection Measurement spectrum set Ref={ref ₁ ,ref ₂ ,...,ref _2m }; When obtaining the measured reflection spectrum information ref _k ′ of an information recording point, search for the corresponding continuously written groove depth information w _k corresponding to the reflection measurement spectrum information ref _k in the correlation relationship, and then write The digital storage information _sk corresponding to the continuous writing groove depth information w _k is used as the digital storage information of the information recording point obtained by decoding. 4. An optical disc reading device based on nanolithography, characterized in that it comprises: The optical path module is used to form a white light source and focus it on an information recording point of the recording layer of the optical disc physical storage medium; it is used to collect optical measurement signals; the measurement optical signal includes the information recording point by its The total reflected light field formed by the coherent superimposition of the reflected light fields of each depth information writing groove

in,

Be the reflected light field of the i-th writing groove of the information recording point; E ₀ is the reflected light field of the unwritten groove; m is the number of bits of the data storage position of the information recording point; "0" and The numbers "1" respectively indicate whether there is a writing groove at the data storage point of the information recording point; n ₁ (λ) is the refractive index of the recording layer of the physical storage medium of the optical disc, which depends on the wavelength λ of the writing beam ;Z _i is the depth of the i-th writing groove, Z ₀ =0 means that the depth information of the unwritten groove is 0; l ₀ is the thickness of the recording layer;/>

Δn=n ₁ -n ₀ , n ₀ is the refractive index of air, and the optical path module includes: a light source, a lens group, a high-magnification objective lens, a beam splitter, and a single lens; The processing module is used to pre-obtain the relationship between the continuous groove writing information w _k on the recording layer of the physical storage medium of the optical disc and the corresponding reflectance measurement spectral information ref _k ; obtain the reflectance measurement from the measurement optical signal After the spectral information ref _k , search for the matching continuous writing groove information w _k corresponding to the reflectance measurement spectral information ref _k in the association relationship, and read it as the digital storage information _sk of the information recording point , the processing module includes: a spectrometer; wherein, the light source is used to emit white light; the lens group is used to collimate and expand the white light and converge it to the beam splitter; the beam splitter , for splitting the received white light and sending it to the high-magnification objective lens; the high-magnification objective lens is used for focusing the received white light on the surface of the physical storage medium of the optical disc to measure the reflection of the recording layer, and collect The measurement light signal is emitted; the single lens is used to converge the measurement light signal to the spectrometer; the spectrometer is used to process the received measurement light signal and decode data storage information therefrom, and the spectrometer includes : a grating spectrometer or a high-speed measurement spectrometer; the high-speed measurement spectrometer includes: an optical dispersion element, a narrow-band integrated filter, and a linear array detector; wherein the optical dispersion element is used to split the received measurement optical signal, to expand the reflection spectrum information in space; the narrow-band integrated filter is used to obtain the light of the wavelength corresponding to the reflection spectrum information dispersed by the optical dispersion element; the linear array detector is used to detect The light intensity of each wavelength of light obtained by the narrow-band integrated filter is detected to obtain reflection spectrum information. 5 . The optical disc reading device according to claim 4 , wherein the light source is a halogen lamp, a tungsten lamp, a xenon lamp, a white LED lamp, a band-pass filtered white light source, or an ultraviolet LED light source. 6. A device for reading and writing an optical disc based on nanolithography, characterized in that it comprises: the device for reading and writing an optical disc based on nanolithography according to any one of claims 4 to 5. 7. The optical disc reading and writing device according to claim 6, wherein the reading device further comprises a third dichroic mirror, which is arranged between the lens group and the beam splitter of the reading device, for To reflect the white light collimated and expanded by the lens group to the high-power objective lens; The beam splitter is used to split the measurement optical signal emitted by the high-magnification objective lens; The single lens is used for converging the measurement optical signal split by the beam splitter to the spectrometer.

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