CN111830614A - A solution for nanograting imprinting using laser polarization state - Google Patents

Abstract

The invention discloses a solution for realizing nanometer grating imprinting by using laser polarization state, wherein a simple structure is designed, and a laser-induced nanometer grating can be used to make a super-resolution pattern, and the weight of nanometer particles can be changed by adjusting the laser wavelength, power and polarization direction. Based on the plastic strength and the orientation of the nanogratings, two methods are proposed to adjust the polarization state of the illumination white light to realize the color control, realize the sensitive induction of polarization, and obtain a high-resolution and high-saturation color with a spatial resolution of 0.5 μm. The formed nano-grating has a polarization control effect on the reflected light. Using the polarization-maintaining and rotation characteristics of the nano-grating to linearly polarized white light, the laser polarization state with an angular resolution of 10° can be identified in a pixel with a spatial resolution of 0.5 μm, and the ultra-high High density optical storage. Compared with the existing SOI (Silicon-On-Insulator, silicon on insulating substrate) etching process, the solution of the present invention has a simple fabrication method and no complicated process.

Description

A solution for nanograting imprinting using laser polarization state

technical field

The invention relates to the technical field of laser-induced periodic structure and color display, in particular to a solution for realizing nano-grating marking by utilizing laser polarization state.

Background technique

As an important sensory medium, color plays an important role in all walks of life. The continuous development of micro-sodium technology and materials for the regulation of light has gone from passively exploiting the limited optical properties of natural materials to actively constructing metamaterials with specific optical properties, of which plasmonic colors have great potential. Using plasmonic subwavelength structures, designing different geometries can achieve selective enhancement at any resonant wavelength or hinder near-field and far-field modulation of optical fields. These periodic nanoparticles or nanorods or nanoholes are mostly prepared by electron beam etching and ion beam etching methods, which are expensive, cannot be fabricated in large areas, and lack dynamic tunability. Laser-induced periodic structures (LIPSs) technology can directly fabricate nano-grating structures on the surface of different bulk materials, avoiding complex lithography processes. Although it can achieve sub-wavelength spatial resolution of polarization orientation, it is all based on the preparation of two-dimensional The orderly linear microstructure is dominant, and it is difficult to display rich colors. Therefore, in the fields of color display and optical storage, the identification of polarization states and the practical application of super-resolution polarization imprinting by this laser direct writing technology need to be further explored.

SUMMARY OF THE INVENTION

In view of this, in order to solve the above problems in the prior art, the present invention proposes a solution for realizing nano-grating imprinting using laser polarization state, which is used for super-resolution color-sensitive display and ultra-high-density optical storage.

The present invention solves the above-mentioned problems through the following technical means:

In one aspect, the present invention provides a sample for realizing nano-grating imprinting by using laser polarization state, the sample includes a substrate, a metal thin film layer, a dielectric isolation layer and a metal nano-island layer in order from the bottom layer to the top layer; the substrate plays a supporting role, It can be a hard flat material such as glass material and silicon wafer; the thickness of the metal film layer is more than 100nm, and the material can be metal such as gold, silver, platinum, aluminum, etc., which is plated on the substrate by evaporation or ion sputtering; The dielectric isolation layer is a flexible material or a hard material, and the flexible material can be an organic thin film, such as PMMA, PVP, PVA and other materials. It is prepared by using a film slinger on the metal thin film layer, and the film slinging speed and film slinging time are controlled. Different film thicknesses; hard materials can be glass or ceramics, such as silicon oxide, aluminum oxide, calcium nitride, calcium carbide, etc., which can be prepared by evaporation or chemical vapor deposition; metal nano-island layers are prepared by particle sputtering The material can be gold, silver, platinum, aluminum and other metals, and the size of the metal nanoparticles is controlled by adjusting the sputtering time and current on the dielectric isolation layer.

On the other hand, the present invention also provides a laser direct writing device for realizing nano-grating engraving by using laser polarization state, including a femtosecond laser system, a laser polarization adjustment device, a shutter, a laser focusing device, a micro-sodium displacement stage, and a laser direct writing device. PC for controlling the program; the sample is placed on the micro-sodium stage, the metal nano-island layer of the sample faces the objective lens port of the laser focusing device, and the laser beam emitted by the femtosecond laser system passes through the laser polarization adjustment device in turn , shutter and laser focusing device, through the laser focusing device, the laser beam is focused on the metal nano-island layer of the sample, and the laser direct writing control program is used to control the micro-sodium stage and shutter, and by moving the micro-sodium stage, pattern writing is realized enter.

The wavelength of the femtosecond laser is changed, so that the strength of the remodeling and imprinting of the metal nano-island by the laser of different wavelengths is different, and the final morphology is also different, so as to control the pattern to present different colors.

The power of the femtosecond laser is changed, so that the strength of the remodeling and imprinting of the metal nano-island by different power lasers is different, and the final morphology is also different, so as to control the pattern to present different colors.

The polarization state of the femtosecond laser is changed, so that the laser with different polarization directions reshapes the metal nano-islands into metal nanoparticles with different orientations and alignment directions after etching, so as to control the pattern to present different colors.

Import the binary image into the laser direct writing control program, guide the micro-sodium stage to move on the 2-dimensional plane according to the pattern requirements, and adjust the laser writing or closing by controlling the shutter switch, so that the femtosecond laser direct writing non-continuous pattern.

The step size of the micro-sodium stage can be set to adjust the size of the pixel and realize the adjustment of the resolution.

In another aspect, the present invention also provides a detection mechanism for realizing nano-grating marking by utilizing the polarization state of laser light, so as to realize the sensitive response of color to polarization. The detection mechanism includes two types: the first type includes a first natural light source, a first adjustable analyzer and a first observation device; the incident natural light irradiated by the first natural light source is vertically irradiated on the image engraved by the laser, and after reflection A first adjustable analyzer is placed on the optical path, and the polarization direction of the first adjustable analyzer is adjusted to obtain linearly polarized reflected light with different polarization directions, and the linearly polarized reflected light with different polarization directions can display different colors. Observe the color change of the pattern of the imprinted image under different analysis angles; the second type includes a second natural light source, a first adjustable polarizer and a second observation device; the incident natural light irradiated by the second natural light source is vertically irradiated on the second natural light source. A tunable polarizer, and then irradiate it on the image engraved by the laser, adjust the angle of the light transmission axis of the first tunable polarizer, change the polarization direction of the white light, and realize that the white light of different polarization directions is irradiated on the engraved image. The second observation device observes the color change of the pattern under illumination of white light with different polarization directions. Color patterns can be observed with both patterns with the same effect.

In another aspect, the present invention also provides an orthogonal polarization analyzer for a detection mechanism that uses laser polarization state to realize nano-grating marking, and identifies the angular resolution of the laser polarization state. The orthogonal polarization analyzer of the detection mechanism includes a third natural light source, a second adjustable polarizer, a second adjustable analyzer and a third observation device; the incident natural light irradiated by the third natural light source passes through the second adjustable polarizer. After the polarizer is adjusted to linearly polarized light, it is irradiated on the pattern engraved by the laser, and the reflected light is then passed through the second adjustable analyzer to observe the laser engraved pattern through the third observation device. The axis direction is always perpendicular to the light transmission axis direction of the second tunable polarizer, and the laser engraved pattern observed under this device presents different light and dark phenomena. Only when the vector direction of the laser-printed nano-grating is consistent with or perpendicular to the transmission axis of the second tunable polarizer, the polarization direction of the reflected light is consistent with the polarization direction of the incident light, and the second tunable analyzer is observed through the second tunable analyzer. No reflected light, it appears black; when the vector direction of the laser-printed nanograting is between 0° and 90° from the transmission axis direction of the second tunable polarizer, the polarization direction of the reflected light rotates, which is different from the incident light. The polarization direction of the light has an included angle, so the reflected light can still pass through the second adjustable analyzer, and then the pattern shape can be observed. When the vector direction of the nano-grating and the transmission axis of the adjustable polarizer are at an angle of 45°, the maximum rotation capability is 45°, the transmittance of the reflected light is the largest, and the brightness of the pattern is the largest; It can achieve 9 polarization states and 10° angular resolution, realizing ultra-high density optical storage.

Compared with the prior art, the beneficial effects of the present invention at least include:

The invention can use laser-induced nano-grating to make a super-resolution pattern, and by adjusting the laser wavelength, power and polarization direction to change the nano-particle remodeling strength and the orientation of the nano-grating, two methods for adjusting the polarization state of the illumination white light to realize color regulation are proposed, The sensitive sensing of color to polarization is realized, and the high-resolution, high-saturation color with a spatial resolution of 0.5 μm is obtained. The formed nano-grating has polarization-maintaining and rotation characteristics for polarized light, and can identify the laser polarization state with a spatial resolution of 0.5 μm and an angular resolution of 10°, realizing ultra-high-density optical storage. Compared with the existing SOI (Silicon-On-Insulator, silicon on insulating substrate) etching process, the solution of the present application has a simple fabrication method and does not require a complex etching process to obtain micro-sodium close to the diffraction limit. Scale patterning and ultra-high density optical storage.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Fig. 1 is the structural representation of the sample that the present invention utilizes laser polarization state to realize nano-grating engraving;

Fig. 2 is the transmission electron microscope (TEM) picture of the gold nano-island of the top layer of the sample of the present invention;

3 is a schematic structural diagram of a laser direct writing device for realizing nano-grating engraving by utilizing laser polarization state according to the present invention;

Fig. 4 is the effect diagram that the laser beam of different polarization states of the present invention is focused on gold nano-island;

5 is a schematic structural diagram of the first detection mechanism for realizing nano-grating engraving by utilizing laser polarization state according to the present invention;

6 is a schematic structural diagram of a second detection mechanism for realizing nano-grating engraving by utilizing laser polarization state according to the present invention;

Fig. 7 is the color diagram of the present invention under the white light of the same polarization direction, the pattern that different laser wavelengths write with the same laser power;

Fig. 8 is the color diagram that the pattern made by the present invention is observed under different polarized white light;

9 is a schematic structural diagram of an orthogonal polarization analyzer of a detection mechanism for realizing nano-grating engraving by utilizing laser polarization state according to the present invention;

FIG. 10 is an effect diagram of the ultra-high density optical storage produced by the present invention.

Description of reference numbers:

1. Sample; 11. Substrate; 12. Metal thin film layer; 13. Dielectric isolation layer; 14. Metal nano-island layer; 21. Femtosecond laser system; 22. Laser polarization adjustment device; 221, 1/2 glass slide; 222 , 1/4 slide; 23, shutter; 24, laser focusing device; 241, total mirror; 242, objective lens; 25, micro-sodium stage; 26, PC; 31, first adjustable analyzer; 32 41, the first adjustable polarizer; 42, the second observation device; 51, the second adjustable analyzer; 52, the third observation device; 53, the second adjustable polarizer.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be pointed out that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, those of ordinary skill in the art can obtain all the Other embodiments fall within the protection scope of the present invention.

Example 1

Referring to FIG. 1 , the present invention provides a sample 1 for realizing nano-grating imprinting by using laser polarization state. The sample 1 includes a substrate 11 , a metal thin film layer 12 , a dielectric isolation layer 13 and a metal nano-island layer 14 sequentially from the bottom layer to the top layer. . The substrate 11 is a glass substrate; the metal film layer 12 is made of gold; the dielectric isolation layer 13 is an organic thin film, made of PMMA; the metal nano-island layer 14 is made of gold.

Preparation method: a layer of gold thin film is plated on the material of the substrate 11 by evaporation method, the substrate 11 plated with the gold thin film is placed on a film slinger, the organic PMMA is prepared into a solution, and the described method is prepared by spin coating. For the dielectric isolation layer 13, different film throwing times and rotational speeds are set according to the thickness requirements. Then, a layer of gold nano-islands with a thickness of 30 nm was prepared on the sample 1 on which the PMMA dielectric isolation layer 13 was plated by using a sputtering apparatus. Please refer to FIG. 2 , a transmission electron microscope (TEM) image of the gold nano-islands on the top layer, where the scale bar is 100 nm.

Example 2

Please refer to FIG. 3 , the present invention provides a laser direct writing device for realizing nano-grating engraving by using laser polarization state, including a femtosecond laser system 21 , a laser polarization adjustment device 22 , a shutter 23 , a laser focusing device 24 , and a micro sodium displacement stage 25 2. A PC 26 with a laser direct writing control program installed, and the laser focusing device 24 is a fluorescence microscope.

The laser pulse transmission path passes through the set femtosecond laser system 21 , the laser polarization adjustment device 22 , the shutter 23 , the fluorescence microscope, and the micro-sodium stage 25 in sequence. The femtosecond laser system 21 outputs femtosecond pulse mode-locked laser light, and the laser polarization adjustment device 22 is used to generate different polarization states of the femtosecond pulse mode-locked laser light; the output polarized light of different polarization states is coupled into the fluorescence through the shutter 23 The objective lens 242 of the microscope is focused on the surface of the metal nano-island layer 14; wherein the sample 1 is placed on the micro-sodium stage 25, and the laser acts on the metal nano-island layer 14 of the sample 1, using femtosecond pulse lock The high energy of the mode laser reshapes the metal nano-islands into metal nanoparticles, and presents a regular arrangement, forming a nano-grating structure and realizing nano-scale imprinting. The PC 26 controls the movement of the micro-sodium stage 25 so that the laser acts on the set area, and the shutter 23 controls the on/off of the laser to realize direct writing of single pixels and discontinuous areas.

The laser polarization adjustment device 22 includes a 1/2 glass slide 221 and a 1/4 glass slide 222, wherein the femtosecond pulsed mode-locked laser passes through the 1/2 glass slide 221 and the 1/4 glass slide 222 in turn, and rotates the two glass slides. Different combinations are obtained to control the polarized light of different polarization states.

The micro-sodium stage 25 and the shutter 23 are controlled by the PC 26, the PC 26 is installed with the laser direct writing control program, and the laser direct writing control program controls the opening and closing of the shutter 23, the micro Movement of the sodium stage 25 in the horizontal plane. Among them, one opening and closing of the shutter 23 completes the marking of one pixel, and the micro-sodium stage 25 moves the sample 1 to complete the marking of different areas.

Laser remodeling of metal nano-islands presents large-scale irregular ellipsoid-shaped gold particles. Due to the effect of laser-induced large-scale gold particle arrays to form nano-gratings, the reshaped nano-islands are regularly arranged into nano-grating structures. The incident light impinging on the nanograting is decomposed into two components parallel to the nanograting vector direction and perpendicular to the nanograting vector direction. The polarization state of the reflected light is determined by the superposition of two reflected components with a phase difference. The resonance peak of the component perpendicular to the vector direction of the nanograting is around 600 nm, and the resonance peak of the component parallel to the vector direction of the nanograting is around 780 nm. By adjusting the polarization angle of the incident light, the size of the two components can be adjusted, and then the two resonance peaks can be adjusted to realize the display of different colors.

The wavelength of the incident laser was continuously changed from 400 nm to 900 nm, and the high energy of the femtosecond pulsed mode-locked laser was used to reshape the metal nano-islands into metal nanoparticles with different morphologies. Due to the high energy of short wavelength, the effect of short wavelength effect is more obvious under the same power. The reshaped metal nanoparticles show a regular arrangement to form nano-gratings and realize nano-scale imprinting.

The power of the incident laser is continuously changed from 0.1mW, and the high energy of the femtosecond pulsed mode-locked laser is used to reshape the metal nano-islands into metal nanoparticles with different morphologies, and exhibit regular arrangement to form nano-gratings, realizing nano-scale imprinting.

Adjust the polarization adjustment device to change the polarization direction (0°～180°) of the incident laser light, change the arrangement and orientation of the metal nano-islands after being reshaped into metal particles, and realize nano-scale imprinting in different directions.

Among them, the binary image to be engraved can be split by color, and the split image is imported into the laser direct writing control program. Each split image is set to a set of laser wavelength, laser power, laser power The parameters of the polarization direction are then linked by the laser direct writing control program to open and close the shutter 23 and the micro-sodium stage 25 to move the sample 1 to complete the engraving of the pattern on the sample 1.

Adjusting the distance of a single step of the laser stage realizes the adjustment of the pixels, and the resolution of the minimum pixel area of 0.5 μm × 0.5 μm can be achieved.

Please refer to Figure 4. Figure 4 shows the effect of laser beams with different polarization states focused on the gold nano-island. Picture a is 0° polarized laser writing, b picture is 45° polarized laser writing, and c picture is 90° laser writing Write, d panel is 135° laser write. It is obvious from the figure that the gold nano-islands are reshaped into directional particles under the action of the laser, and the particles are regularly arranged to form a nano-scale grating, and the vector direction of the grating is parallel to the laser polarization direction.

Example 3

The present invention also provides a detection mechanism for realizing nano-grating engraving by using laser polarization state to control the color. There are two schemes. The first scheme: please refer to FIG. 5, the detection mechanism includes a first natural light source, a Adjustable analyzer 31 and first observation device 32; wherein the first natural light source is a first halogen lamp, and the first observation device 32 is a first microscope. The natural light irradiated by the first halogen lamp is vertically irradiated on the image engraved by the laser, the first adjustable analyzer 31 is placed on the reflected light path, and the angle of the light transmission axis of the first adjustable analyzer 31 is adjusted to make different polarizations. The reflected light in the direction is transmitted, and the color change of the pattern of the imprinted image under different analysis angles is observed through the first microscope. The second solution: please refer to FIG. 6, the detection mechanism includes a second natural light source, a first adjustable polarizer 41 and a second observation device 42; wherein the second natural light source is a second halogen lamp, and the second observation device 42 is a second microscope. The natural light irradiated by the second halogen lamp is vertically irradiated on the first adjustable polarizer 41, and then irradiated on the image engraved by the laser, and the angle of the light transmission axis of the first adjustable polarizer 41 is adjusted to change the polarization direction of the white light. , to realize that white light of different polarization directions is irradiated on the imprinted image, and the color change of the pattern under the irradiation of white light of different polarization directions is observed through a second microscope. Due to the different laser parameters imprinted on the sample 1, the reshaped morphology and arrangement orientation of the metal nanoparticles are different. In the above two detection mechanisms, the color of the image can be changed by adjusting the angle of the light transmission axis of the polarizer to achieve color. The polarization-sensitive response, as well as modulation.

Please refer to FIG. 7 for the effect of this embodiment. The abscissa of the above figure represents the power of the 750nm, 0° polarized laser, and the ordinate represents the polarization direction of the incident polarized white light. Since the angle between the polarization direction of the white light and the grating structure is in the vector direction Symmetrical distribution, just show the 0°-90° polarized white light illumination pattern. The patterns do not have rich colors under natural light, but show different colors under natural light and polarized white light illumination in different directions, indicating that the written patterns have obvious polarization sensitivity. The abscissa of the figure below represents the power of the laser, and the ordinate represents different laser wavelengths. The pictures are all observed under 0° polarized white light. It is obvious from the figure that under the white light of the same polarization direction, the colors of the patterns written by different laser wavelengths and the same laser power are different.

For the effect of this embodiment, please refer to Figure 8. The pattern is divided into different pictures according to the different colors to be printed, and the corresponding laser parameters are set for each picture. 280 microns. Then write the pattern through the laser direct writing device according to the set laser parameters. Observing the pattern under 0° polarized white light shows rich colors, and the color presented under 90° polarized white light is completely different from the 0° case, with obvious polarization sensitivity. The veins in the leaves are clearly visible, and the minimum interval between the veins is 700nm, which is close to the optical diffraction limit and realizes super-resolution display.

Example 4

The present invention also provides an orthogonal polarization analyzer of a detection mechanism that utilizes laser polarization state to realize nano-grating marking, and performs polarization state resolution analysis, please refer to FIG. 9 , the orthogonal polarization analyzer of the detection mechanism includes a third natural light source, The second adjustable polarizer 53 , the second adjustable analyzer 51 and the third observation device 52 ; the incident natural light irradiated by the third natural light source is adjusted to linearly polarized light after passing through the second adjustable polarizer 53 . On the laser-engraved pattern, the reflected light passes through the second adjustable analyzer 51 to observe the laser-engraved pattern through the third observation device 52, wherein the direction of the light transmission axis of the second adjustable analyzer 51 is always the same as that of the second adjustable analyzer 51. The light transmission axis of the polarizer 53 is perpendicular to form an orthogonal polarization analyzer. The nano-grating has a regulating effect on polarized light. When the incident polarized white light is parallel and perpendicular to the vector direction of the nano-grating, the polarization direction of the reflected light is consistent with the incident light, and has polarization-maintaining properties. Therefore, the reflected light passes through the second adjustable analyzer 51 When the incident polarized white light and the nanograting vector direction form an included angle of 45°, the control effect on the polarized white light is the greatest, and the polarization direction of the reflected light rotates 45° to the nanograting vector direction, and when the angle is less than 45° , the rotation ability of the polarized light is weak, and the angle between the polarization direction of the reflected light and the polarization direction of the incident light is less than 45°, so after the reflected light passes through the analyzer, there is still light passing through, and the pattern can be observed. Using the polarization-maintaining and rotating properties of the nanograting to polarized white light, the readout of the laser-written pattern in a specific polarization direction can be achieved, and the resolution of the polarization state can be obtained.

For the effect of this embodiment, please refer to Figure 10. Each letter in the character "#Advanced materials#" is written with a laser polarization state, which are 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, 180°. The polarization direction of the polarizer was changed at 10° intervals, and the pattern was observed under an orthogonal polarization analyzer to change light and dark with one cycle of 90°. When the laser polarization state is parallel and perpendicular to the polarization direction of the polarizer, it is completely filtered out. When the laser polarization state and the polarization direction of the polarizer are at an angle of 10°, the pattern can be clearly observed. Nine polarization states, 10° angular resolution, where the pattern is written with pixels of 0.5 μm × 0.5 μm, achieving a spatial resolution of 0.5 μm, in addition, 3 colors are written in combination with the 3 laser wavelengths in Figure 7, so it is possible to record 3 × 9 species, enabling ultra-high-density optical storage.

The invention can use laser-induced nano-grating to make a super-resolution pattern, and by adjusting the laser wavelength, power and polarization direction to change the nano-particle remodeling strength and the orientation of the nano-grating, two methods for adjusting the polarization state of the illumination white light to realize color regulation are proposed, Sensitive sensing of polarization is achieved, and high-resolution, high-saturation colors with a spatial resolution of 0.5 microns are obtained. The formed nano-grating has a polarization control effect on the reflected light. Using the polarization-maintaining and rotation characteristics of the nano-grating to linearly polarized white light, the laser polarization state with an angular resolution of 10° can be identified in a pixel with a spatial resolution of 0.5 μm, and the ultra-high High density optical storage. Compared with the existing SOI (Silicon-On-Insulator, silicon on insulating substrate) etching process, the solution of the present application is simple in fabrication method and does not require complicated processes.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (10)

1. a kind of sample that utilizes laser polarization state to realize nanometer grating imprinting, it is characterized in that, from bottom layer to top layer sequentially comprises substrate, metal thin film layer, dielectric isolation layer and metal nano-island layer. 2. The sample for realizing nano-grating engraving by laser polarization state according to claim 1, characterized in that, the substrate plays a supporting role, and a hard flat material of glass or silicon wafer is used; the thickness of the metal film layer is more than 100 nm, A metal material of gold, silver, platinum or aluminum is used to coat the substrate by evaporation or ion sputtering; the dielectric isolation layer is a flexible material or a hard material, and the flexible material is an organic thin film, including PMMA, PVP or PVA, prepared by using a film slinger on the metal thin film layer, controlling the film slinging speed and film slinging time to achieve different film thicknesses; the hard material is glass or ceramics, including silicon oxide, aluminum oxide, calcium nitride or carbide Calcium, prepared by evaporation or chemical vapor deposition; the metal nano-island layer is prepared by particle sputtering, using gold, silver, platinum or aluminum metal materials, on the dielectric isolation layer by adjusting the sputtering time and current control the size of metal nanoparticles. 3. a laser direct writing device utilizing laser polarization state to realize nano-grating engraving, is characterized in that, comprises any described sample of claim 1-2, also comprises femtosecond laser system, laser polarization adjustment device, shutter, laser Focusing device, micro-sodium stage and PC with laser direct writing control program; The sample is placed on the micro-sodium stage, and the metal nano-island layer of the sample faces the objective lens port of the laser focusing device; The femtosecond laser system outputs a femtosecond pulse mode-locked laser, and the laser polarization adjustment device is used to generate different polarization states of the femtosecond pulse mode-locked laser; the output polarized light with different polarization states is coupled into the laser focusing device through a shutter. The objective lens focuses on the surface of the metal nano-island layer; the laser acts on the metal nano-island layer of the sample, and uses the high energy of the femtosecond pulsed mode-locked laser to reshape the metal nano-islands into metal nanoparticles, and presents regular patterns Arrangement of nanometer gratings to achieve nanoscale imprinting; The laser direct writing control program controls the movement of the micro-sodium stage, so that the laser acts on the set area, the laser direct writing control program controls the opening and closing of the shutter, and the shutter controls the on and off of the laser, so as to realize a single pixel and a discontinuous area direct writing. 4. The laser direct writing device utilizing laser polarization state to realize nano-grating engraving according to claim 3, is characterized in that, described laser polarization adjustment device comprises 1/2 glass slide and 1/4 glass slide, femtosecond pulse lock The mode laser passes through the 1/2 glass slide and the 1/4 glass slide in turn, and rotates the two glass slides to obtain different combinations to control the polarized light of different polarization states. 5. The laser direct writing device utilizing laser polarization state to realize nano-grating engraving according to claim 3, is characterized in that, changing the wavelength of femtosecond pulse mode-locking laser, so that different wavelength lasers reshape the metal nano-isles and The strength of the engraving is different, and the final shape is also different, so as to control the pattern to show different colors; Change the power of the femtosecond pulse mode-locked laser, so that the strength of the remodeling and imprinting of the metal nano-island by different power lasers is different, and the final morphology is also different, so as to control the pattern to show different colors; The polarization state of the femtosecond pulse mode-locked laser is changed, so that the laser with different polarization directions reshapes the metal nano-islands into metal nanoparticles with different orientations and alignment directions after etching, so as to control the pattern to present different patterns. color. 6. The laser direct writing device utilizing laser polarization state to realize nano-grating engraving according to claim 3, wherein the laser direct writing device splits the binary image that needs to be engraved by color, and the split The image is imported into the laser direct writing control program, and each split image sets a set of parameters of laser wavelength, laser power, and laser polarization direction according to different colors, and then the laser direct writing control program is linked to the opening and closing of the shutter , The micro-sodium stage moves the sample to complete the engraving of the pattern on the sample. 7 . The laser direct writing device utilizing laser polarization state to realize nano-grating engraving according to claim 3 , wherein the step size of the micro-sodium displacement stage is set to adjust the size of the pixel to realize the adjustment of the resolution. 8 . 8. A detection mechanism for realizing nano-grating engraving by utilizing laser polarization state to realize the sensitive response of color to polarization, wherein the detection mechanism comprises a first natural light source, a first adjustable analyzer and a first observation device ; The incident natural light irradiated by the first natural light source is vertically irradiated on the image engraved by the laser, a first adjustable analyzer is placed on the reflected light path, and the angle of the light transmission axis of the first adjustable analyzer is adjusted to make different polarization directions. The reflected light is transmitted through, and the color change of the pattern of the imprinted image under different analysis angles is observed through the first observation device. 9. A detection mechanism for realizing nano-grating engraving by utilizing laser polarization state to realize the sensitive response of color to polarization, wherein the detection mechanism comprises a second natural light source, a first adjustable polarizer and a second observation device ; The incident natural light irradiated by the second natural light source is vertically irradiated on the first adjustable polarizer, and then irradiated on the image engraved by the laser, and the angle of the light transmission axis of the first adjustable polarizer is adjusted to change the polarization direction of the white light. It is realized that white light with different polarization directions is irradiated on the imprinted image, and the color change of the pattern under the irradiation of white light with different polarization directions is observed through the second observation device. 10. A detection mechanism orthogonal polarization analyzer for realizing nano-grating engraving using laser polarization state to identify the angular resolution of the laser polarization state, characterized in that the detection mechanism orthogonal polarization analyzer comprises a third natural light source, a third Two adjustable polarizers, a second adjustable analyzer and a third observation device; The incident natural light irradiated by the third natural light source is adjusted to linearly polarized light after passing through the second adjustable polarizer, and irradiated on the pattern engraved by the laser, and the reflected light is then passed through the second adjustable analyzer to observe the laser light through the third observation device. An engraved pattern, wherein the direction of the light transmission axis of the second adjustable analyzer is always perpendicular to the direction of the light transmission axis of the second adjustable polarizer, and the observed laser engraved pattern presents different light and dark phenomena; Only when the vector direction of the laser-printed nano-grating is consistent with or perpendicular to the transmission axis of the second tunable polarizer, the polarization direction of the reflected light is consistent with the polarization direction of the incident light, and the second tunable analyzer is observed through the second tunable analyzer. No reflected light, it appears black; when the vector direction of the laser-printed nanograting is between 0° and 90° from the transmission axis direction of the second tunable polarizer, the polarization direction of the reflected light rotates, which is different from the incident light. The polarization direction of the light has an included angle, so the reflected light can still pass through the second adjustable analyzer, and then the pattern shape can be observed; when the vector direction of the nano-grating and the direction of the transmission axis of the adjustable polarizer are at an included angle of 45° , the rotation ability is up to 45°, the transmittance of the reflected light is the largest, and the brightness of the pattern is the largest; using the polarization-maintaining and rotation characteristics of the nano-grating to polarized white light, the read-out of the laser-written pattern in a specific polarization direction is realized, and the polarization is obtained. state resolution, enabling ultra-high-density optical storage.

Images