RU2545494C1 - Digital holographic method - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention may be used as a measurement system for non-invasive express diagnostics of multi-component biological media for detection of viruses, bacteria and other microorganisms. A microscope comprises a source of radiation, a focusing lens, a diaphragm and a cuvette for placement of the examined object, arranged along the optical axis, a matrix of photodetectors, an electronic-computing system, including a unit of processing, software and a PC. Additionally upstream the cuvette there is a filter to smoothen Gaussian distribution of a radiation beam and to produce even lighting along the beam cross section. The cuvette has a transparent flat input window. The output window of the cuvette has the shape of the hemisphere with a radius equal to the distance from the input to the output window of the cuvette. The matrix of photodetectors has the shape of the hemisphere, which is located in parallel to the output window of the cuvette, follows its shape and is rigidly connected to it.

EFFECT: preservation of identical light force along cuvette cross section and increased resolution of a DHM.

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Description

The invention relates to a digital holographic microscope (CTM) and can be used as a measuring system for non-invasive express diagnostics of multicomponent biological media containing the studied object in order to determine viruses, bacteria and other microorganisms in water bodies, on the Earth and on other space bodies by digital recording a hologram of the medium (including liquid) and digital restoration of its image while maintaining the amplitude and phase of the wave. DIHM (Digital In-Line Holographic Microscope) also allows you to determine the characteristics of the scattering of the intensity of electromagnetic radiation on the studied object, its distribution over the volume of the medium, determining the depth and its position in 3- and 4-coordinate space, the direction of movement (track), speed , size, accumulate information, compare the object with test objects, etc.

TsGM refers to measuring systems for automatic control, technical diagnostics, pattern recognition systems (objects) and transmission of measurement information. Such devices are used on the surface of the Earth, in wells, or at different depths of water bodies to determine their biological components. The system allows full automation.

The emergence of CGM devices was facilitated by the development of the modern element base of microelectronics - the advent of laser semiconductor and quasicoherent LEDs, CCD (Charge-Coupled-Device), CMOS (Complementary Metal-Oxide-Semiconductor) photodetectors and other matrices (hereinafter referred to as “matrices”), as well as the implementation of various image processing algorithms on stationary and laptop PCs, allowing you to create mobile, autonomous and portable tools for implementing a network remote express analysis system at various points and process data in real time.

A CTM can restore an image of a given object from a volume of a biological medium of complex composition.

Objects can be crustaceans, bacteria and other microorganisms, as well as, for example, microparticles, traces of nuclear charged particles in a bubble chamber irradiated at accelerators / 1 /, etc.

/ 1 / [Turukhano B.G. Accumulation of information on the hologram by the depth of the reconstructed image and loading of the bubble chamber with tracks. ZhTF, vol. 90, No. 1, pp. 181-187, vol. 1970].

The device is able to save all the data in its database and analyze them in real time or ex post. Moreover, these processes and data processing can be carried out in automatic mode / 2 /.

/ 2 / [MATLAB Advisory Center SoftLine company http://www.nsu.ru/matlab/MatLab_RU/default.asp.htm].

To solve a wider and more complete range of tasks and determine the coordinates of point objects, another program was completed and became available / 3 /.

/ 3 / [Program for restoring holographically recorded images and determining the spatial location of point objects "Digital Holography". " Certificate of official registration of the computer program No. 20099614972 of September 11, 2009].

These programs allow you to complete a complete circle of registration of a hologram using an array of photodetectors and process its reconstructed image.

A TsGM device, in the general case, consists of two parts: optical, which is necessary for creating a holographic interference picture (hologram), and electronic and computing for digital recording, reading and processing of the obtained data in real time or after the fact.

In general, when recording a hologram, a coherent radiation source is used, as a rule, a laser, gas / solid-state (in stationary systems) or solid-state (in portable devices), a coaxial two-beam optical scheme in which the volume (cuvette) with the object under study is located, and hologram detector in the form of a matrix of photodetectors. The best resolution of the object under study was achieved at 225 nm / 4 / using ultraviolet radiation (λ = 372 nm) and a CMOS matrix with a pixel of 1.12 μm, while the authors performed mathematical processing of the data to increase the resolution of the recording photodetectors (pixels).

/ 4 / [Aloon Greenbaum, Aydogan Ozkan. Increased space-bandwidth product in pixel super-resolved lensfree on-chip microscopy. Scientific Reports, published 24 April 2013].

However, currently existing systems and programs for DTMs provide only a tool that allows you to best and automatically determine the characteristics of the object under study with a given configuration of a particular DTM, but do not solve one of the important issues, namely the issue of increasing the resolution of the system at the recording stage holograms. Therefore, taking into account the available hardware, mathematical and computer capabilities, it is necessary to find such DTM constructions that would increase its resolution at the level of hologram registration.

It is known TsGM / 5 / consisting of two systems: an optical system for recording a hologram and a system for reading information from a hologram in real time using a GPU chip (a device for graphic and digital information processing). The GPU calculates the Fresnel diffraction of light on the object under study, recorded on the hologram, and restores its image.

/ 5 / [Tomoyoshi Shimobaba, Nobuyuki Masuda and Tomoyoshi Ito. Multi-view and multi-resolution real-time digital holographic microscopy. Microscopy: Science, Technology, Application and Education, 1419-1425, 2010].

The optical system contains a coherent radiation source (laser), a cuvette with the studied objects and with flat windows and recording the flat matrix of the CCD camera. The image of the interference pattern (Gabor hologram / 6 /) is recorded on the matrix of a CCD camera, the resolution of which is 1360 × 1024 pixels with a pixel size of 4.65 μm × 4.65 μm.

/ 6 / [D. Gabor. A new microscopic principle. Nature 161, pp 777-778, 1948].

The device TsGM works as follows.

The light wave from the laser at the entrance to the interferometer is divided into two parts, passing along its two shoulders.

One part of the wave passes through the shoulder, where the studied object is located, diffracting on it, after which it, at the exit from the interferometer, meets the second part of the wave passing undistorted through the second shoulder and interferes with it. From the optical system of the device, the image is transferred to the second system for restoring, reading and processing information using the GPU and PC.

Information about the object under study is a hologram in the form of a Fresnel diffraction pattern (interference fringes of various shapes and with different distances between them), which is recorded on a CCD camera matrix. The hologram is then decoded (restored) using the GPU and PC.

The disadvantage of the TsGM device is the recording on the hologram of the interference pattern of mainly the low-frequency spectrum, as a result of which the system allows the restoration of objects with low resolution. This is due to the fact that the aperture of the matrix of the recording device of the CCD camera is small and part of the high-frequency spectrum of the interference pattern located at the periphery of the hologram is cut off and lost.

Another disadvantage is the Gaussian (bell-shaped) intensity distribution over the laser beam cross section; therefore, the interferogram recorded in the plane of the CCD camera’s matrix is different in brightness along the entire plane of the hologram, which determines the recording quality, and when reading it leads to a different signal-to-noise ratio over field of the matrix and, as a consequence, the possibility of increasing random errors during image recovery and processing of data obtained from the hologram.

Of the known TsGM devices, the closest in technical essence is the TsGM described in / 7 /.

/ 7 / [S.K. Jericho, P. Klages, J. Nadeau, E.M. Dumas, M.H. Jericho, H.J. Kreuzer. In-line digital holographic microscopy for terrestrial and exobiological research. Planetary and Space Science 58, p. 701-705, 2009].

A digital holographic microscope contains a radiation source having an optical axis directed in the direction of beam propagation, a focusing lens, an aperture, and a cuvette with an object under study that are located on the optical axis. The cuvette has flat - entrance and exit windows. Further, the central digital computer contains a flat matrix of a CCD camera with photodetectors, an electronic computer system, including a data processing unit, software that allows you to restore the image of an object and a PC.

The device operates as follows.

The laser beam is focused using the lens in the plane of the diaphragm. After the diaphragm, the wave diffracts on the object and scatters in the form of spherical waves that interfere with light waves passing in the same direction without scattering, creating an interference pattern that is fixed to the matrix of the CCD camera.

The hologram is stored on the flat matrix of the CCD camera in the form of a 2-coordinate interference pattern, on which the amplitude and phase of the wave scattered by the object are recorded simultaneously. Further, the picture is digitally restored. The essence of the restoration is to obtain a complete 3-coordinate image of the object from a 2-coordinate hologram, which is possible due to the fact that the phase and amplitude of the wave diffracted on the object were simultaneously recorded on the hologram. A series of holograms taken at different times at a certain speed allows you to restore the 4-coordinate path of the object. The authors obtained a resolution of about 2 microns.

The disadvantage of this device is the recording on the hologram, mainly of the low-frequency spectrum of the interference pattern, as a result of which the system allows you to restore objects with limited resolution. This is due to the fact that the aperture of the recording flat matrix of the CCD camera is small, and the high-frequency part of the spectrum of the interference pattern located on the periphery of the hologram falls out of the general context. In addition, due to the Gaussian distribution of the laser beam, the interferogram recorded in the plane of the matrix of the CCD camera is not identical in brightness and contrast.

The objective of the proposed invention is:

- maintaining the same aperture in the cross section of the volume with the studied objects;

- an increase in the resolution of the CTM;

- increase in volume with the studied objects while maintaining its compactness.

The task is achieved by the fact that in the well-known DGM containing a radiation source having an optical axis directed towards the propagation of the radiation beam, a focusing lens, aperture and a cuvette for placing the object under study located along the optical axis, and the cuvette has transparent input and output windows, and the input window is flat, the matrix of photodetectors, an electronic computer system including a processing unit, software that allows you to restore the image of the object in static and in motion, and PC, it is new that, in addition to the cuvette, a filter is introduced to smooth the Gaussian distribution and obtain uniform illumination over the beam cross section, the output window of the cuvette has the shape of a hemisphere with a radius equal to the distance from the input to the output window, and the photodetector matrix has the shape of a hemisphere, located in parallel the output window of the cell, repeats its shape and is rigidly connected with it.

Such a combination of features in the claimed HMC allows you to:

1 - to provide uniform illumination over the beam cross section by smoothing the Gaussian distribution of the radiation source;

2 - increase the resolution of the HMC by increasing the aperture of the photodetector array and its shape in the form of a hemisphere, which allows recording high-frequency interference fringes of the hologram;

- increase the volume with the studied object while maintaining the compactness of the claimed device.

Figure 1 is a block diagram of the MHC. Figure 2 shows a specific example of a structural solution of the proposed device TsGM. In Fig. 3, for comparison, the pattern of interference of beams is given in the case of using a HMC device with a hemispherical matrix and with a flat one.

The device consists of optical and electronic computing systems. The optical circuit contains a laser 1, a micro lens 2, an aperture 3, a filter 4, a cuvette with an object under study 5, a matrix 9, and an electronic computer system contains a data processing unit 11 and a PC 12.

Figure 2 shows a specific example of a constructive solution of the proposed HMC device for recording a lensless Fresnel hologram with a point source of an auxiliary wave, where 1 is a radiation source (laser), 2 is a micro lens, 3 is an aperture, 4 is a filter for smoothing the Gaussian distribution, 5 is cuvette with the studied object, 6 — flat entrance window of the cuvette, 7 — hemispherical exit window of the cuvette, 8 — studied object, 9 — hemispherical matrix repeating the shape of the output window of the cuvette 7 and consisting of photodetectors, θ1, θ2, θ3, θ4 - angle s between the object and auxiliary rays involved in creating a hologram on the inner surface of the hemispherical matrix.

In figure 3. a comparison is made of the patterns of interference of beams at the same time in the case of using a HMC device with a hemispherical matrix proposed in this application (solid lines) and with a flat prototype matrix (dashed lines). The flat matrix of the CTG prototype 10, and θ5, θ6, θ7, θ8, are the angles between the object and auxiliary rays involved in creating the hologram on the inner surface of the flat matrix of the prototype.

The device operates as follows: the beam from the radiation source 1 (Figure 1) falls on a micro lens 2, which focuses it. A diaphragm 3, ranging in size from a few units to fractions of a micron, is cut off at the focus of the micro-lens, cutting off high frequencies in the focus of the micro-lens in order to clear it of coherent noise caused by diffraction by lens defects and particles that fall in the path to the object under study. After this, the beam passes through the filter 4, which smooths its Gaussian distribution and turns it into a uniform over the entire cross section. Further, the beam through a flat entrance window 6 enters the cell 5 with the studied object 8, diffracting on it and heading through the transparent exit window in the form of a hemisphere 7 towards the hemispherical matrix 9. The cell at its base (entrance window 6) has an inlet that allows passing through it a stream with the studied objects, and an outlet for the output of this stream. As can be seen from Figure 2, all the rays scattered by the object within the hemisphere interfere with the corresponding auxiliary (undistorted) rays at angles θ1, θ2, θ3, θ4 and fall on the hemispherical matrix, creating a picture in the form of interference fringes. 3, the dotted line shows the rays diffracted by the object, interfering with the reference rays at angles θ5, θ6, falling on a flat matrix used in the prototype as a recording hologram, and in this case, θ7, θ8, which cannot get on the matrix in the strength of its limited size will be reflected due to the small angle with a flat matrix, without giving interference. With a significant increase in the size of the flat screen, the aperture of peripheral rays incident on the matrix, especially at angles θ7, θ8, is much smaller due to their large divergence, oblique incidence, and distance from the system axis compared to the aperture of rays that are detected closer to the axis. In this case, it is difficult to write a hologram on the matrix with which you can get an image of an object with improved resolution. For this, it is necessary to have a very large dynamic range of photosensitivity of photodetectors, while when recording on a hemispherical matrix, the aperture ratio of the rays is preserved on almost the entire surface of the matrix due to the small distance from the source of spherical waves - the diaphragm.

Figure 3 shows that the angles θi (j) (i = 1, 2, 3, 4 for a hemispherical matrix; j = 5, 6, 7, 8 for a flat matrix) between the diffracting rays on the object and the rays of the reference wave grow along as you move away from the axis of the system and approach the input window of the cell 6, i.e.:

respectively, and their sinuses sinθi (j) also grow

and according to the formula

the frequency ν of the interference bands formed as a result of their interference also increases. In Fig. 3, the interfering rays converge in solid lines on the inner surface of the hemispherical screen, and in dashed lines the flat screen of the HMC. T.O. in the case of a planar matrix, the intersection of the rays with distance from the axis is also at a great distance from it, which requires much larger dimensions of the planar matrices.

The maximum angle formed by the reference and diffracted rays close to the entrance window of the cell gives the intersection of a plane matrix close to infinity, and this requires a significant increase in its size, which is practically unrealizable. On the other hand, recording the interference of these peripheral rays is necessary to increase the resolution of the system.

Such large dimensions of a flat matrix, and therefore the system as a whole, are inconvenient not only for a portable, but even for a stationary system, because in this case, it is necessary to increase the vibration resistance and thermal stability of the system, which affect the quality (resolution) of the hologram. It is especially important when recording on a hologram interference fringes of high frequency and, accordingly, small periods, so that these fronts accurately maintain their position relative to each other in space and time. The shorter the period of the bands recorded by the hologram, the higher should be its resolution.

Hologram resolution

The resolution of the hologram R according to the Rayleigh criterion is given by the expression:

where k is a constant coefficient depending on the shape of the matrix,

λ is the wavelength of the radiation source, f is the distance from the object to the recording screen, D is the aperture of the matrix.

The resolution of the HMC, according to expression (1), depends on the following factors:

a) λ is the wavelength of the radiation source

When creating a hologram with a high resolution in a HMC, it is desirable to use a radiation source having the shortest possible wavelength λ, which leads to an increase in the frequency of interference fringes in the plane of registration of the hologram, and subsequently, when restoring the hologram, to a higher resolution of the reconstructed image of the object / s and expanding the frequency range of the image of the object. However, working in the UV region and with λ <0.3 μm is difficult, and at the same time, the effect of UV radiation on the biological objects under investigation is ambiguous. Therefore, sources of small λ in the visible region of the spectrum, taking into account their non-destructive effect on the object under study, are selected into existing HMCs when studying biological objects.

b) Aperture D (size) of the DTM matrix

The aperture D (size) of the matrix is linearly related to the resolution of the CMG.

The aperture of the recording matrix, in existing HMC systems, depends on a number of factors: restrictions on the geometric dimensions and allowable weight determined by specific tasks in each individual case.

The small dimensions of the central gas station are associated with the use of the inventive device on the ground, in space and underground, with its immersion, for example, at great depths (up to several kilometers), where the diameter of the wells or submersible devices is limited by technical and technological conditions, or when they are raised in space, where there is also a strong restriction on the size and weight of aircraft;

Due to the small aperture of the recording matrices, HMCs using the Gaborov coaxial (online) holography scheme register low spatial frequencies of the interfering beams that appear as a result of interference at small angles between the object and reference beams. Large angles between these beams, responsible for the high spatial frequencies that determine the high resolution of the reconstructed image of the object under study, are located on the periphery of the hologram and go beyond the dimensions of the recording matrix.

In the case of applying the online hologram recording scheme using a coaxial reference beam in the plane of the hologram registration, there is interference of two beams with increasing spatial frequency to the periphery. According to the definition of the transfer function, in the optical part of the CGM, the transfer function A (νx, νy) is the ratio of the output signal to the input in the frequency representation:

where E (νx ′, νy ′) and I (νx, νy) are the distribution of the illumination of the image (output signal) and brightness of the object (input signal), νx ′, νy ′ are the spatial frequencies of the image, νx, νy are the spatial frequencies of the object . In this case, the spatial frequency in the object space ν and the spatial frequency in the image space ν ′ are connected by a linear dependence:

where β is the linear increase in the system.

Therefore, the loss of high frequencies (at the input) when registering the interference pattern on the DTM matrix, which is responsible for the fine structure of the object, will be directly and linearly associated with the loss of the same frequencies in the space of the reconstructed image (at the output), which leads to a decrease in the transfer function A (νx , νy) and the resolution of the system as a whole. Thus, an increase in the resolution of the HMC can be achieved by linearly maintaining the balance of all frequencies of the object and its reconstructed image, due to the registration of high frequencies of interference fringes recorded on the matrix at a given wavelength λ.

It is known that the spatial frequency of interference fringes ν, in turn, depends on the angle θ between the interfering beams (diffracted on the object and reference) and the wavelength λ of the radiation source, according to the expression

As can be seen from expression (4), the larger the angle θ, the higher the frequency of the interference fringes recorded on the hologram, and, accordingly, the smaller the distance between them, and therefore, the higher the resolution should be for their spatial separation.

Raleigh suggested that (in our case) two interference bands of equal intensity recorded on the hologram begin to resolve when the main intensity maximum of one band coincides with the first minimum of the other band. The ratio of intensities at the midpoint to intensity at the maximum is 0.811.

Near the optical axis of the hologram, the angles are small (FIGS. 2 and 3), and their increase occurs as the object wave moves away from the optical axis, i.e. to the periphery of the hologram.

It should be noted that it is possible to process data from a hologram to achieve a high resolution image, but only within the frequencies recorded by the flat matrix. In order to register a high-frequency matrix, work was carried out to bring the object closer to the matrix / 8 / and then digitally process the data.

/ 8 / [Ulf Schnars and W PO Juptner. Digital recording and numerical reconstruction of holograms. Meas. Sci. Technol., 13, R85-R101, 2002].

When a flat matrix detects an interference pattern created by reference and object rays incident on it at small angles relative to its plane, a part of the rays diffracted by the object is detected by the matrix, and a part is reflected from its plane.

It is known that the law of light reflection is valid not only for ideally reflecting surfaces, but also for the boundary of two media partially reflecting light, as in the case of a matrix with light receivers having both flat and spherical input windows - lenses (for example, CMOS sensors) Moreover, the law does not state the ratio of reflected and absorbed light. Moreover, starting from a certain angle of the object rays, they are completely reflected, which will lead to the fact that the corresponding interference bands will not be recorded by the matrix at all, thereby eliminating the extreme part of the matrix from the general registration process, and, accordingly, higher peripheral (extreme) frequencies that should have been recorded on it.

In the case when the distances from the studied object to the planar matrix are small, the Fresnel approximation is no longer valid and in order to obtain high resolution it is necessary to conduct digital processing taking into account the characteristics of the pixel (type, density and area). Such processing is needed to increase the resolution of the system and increase the signal-to-noise ratio to reduce the likelihood of false signals during restoration of the object and its characteristics. In addition, when trying to approximate the studied objects to the matrix, the working volume of the cell decreases, and the time for collecting statistical data increases

c) f is the distance from the object to the recording screen

The resolution of the system increases with decreasing f (see (1). Figure 3 shows that the path of the rays propagating from the object to the hemispherical matrix - f _cm (solid lines) is always less than the length of the path from the object to the plane matrix (prototype case) - f _plm (their continuation is indicated by a dotted line), i.e. f _sfmAi <f _plm (Ai + Bi) (Ai is the segment of the beam to the hemispherical matrix, Bi is the segment of the beam to the flat matrix, i is the conditional ordinal number beam, increasing with distance from the optical axis.) The exception is only rays coinciding e with the optical axis (i = 0):

f _sfmAo <f _plmBo , because Ao = Bo.

Because for this object 8, shown in figure 3:

and the corresponding

it is obvious that the resolution of a HMC with a hemispherical screen will be higher in comparison with a flat screen, and, as can be seen from expressions (1) and (6), in this case the resolution of a flat screen is not only lower than that of a hemispherical screen, but it is falls with distance from the axis, because to the periphery f, _plm increases substantially.

The increase in the resolution of the HMC is affected by:

a) the intensity distribution of the radiation beam.

Maintaining the same intensity over the entire cross section of the beam of the radiation source perpendicular to the optical axis, in order to obtain the same intensity of interference fringes on the surface of the matrix, which registers the hologram. Recording a hologram with different intensities of interference fringes will lead to additional problems in processing reconstructed from the information matrix.

The beam intensity of a coherent radiation source has a Gaussian distribution (bell), at which the center is bright and the periphery is weaker, therefore, in different places of the volume with the studied objects there is a different aperture and therefore these objects are illuminated differently, which determines the different amplitude of the electrical signals recorded with photodetectors of the matrix, and subsequently the nature and quality of digital image processing.

Conversion of a Gaussian bell-shaped beam intensity distribution over the cross section into a uniform one can be carried out using a filter in the form of an amplitude-phase mask, which smooths the intensity distribution by raising the brightness at the periphery, and also using a Gaussian filter, which is one of the smoothing filters.

Also known are πShaper 12_12 filters, which convert the Gaussian distribution of the laser beam into a rectangular distribution in the visible as well as in the UV part of the spectrum (in this case, it is more convenient to install these filters to expanding optics).

The simplest rectangular Gaussian smoothing filter also averages the radiation intensity over the entire beam section;

b) an increase in the aperture D of the matrix, made in the form of a hemisphere, due to which the high-frequency part of the hologram is recorded.

The purpose of increasing the resolution:

- resolution of the closest interference lines formed in the plane of the matrix during registration of the hologram, and

- an increase in resolution over the entire volume under investigation, thanks to the creation of a hemispherical matrix and a cuvette to preserve the compactness of the DTM.

It is known that the resolution of a hologram is proportional to its size.

The hemispherical matrix (see Figure 3) has a larger size (area / perimeter) (2πR ² / πR) than the flat square matrix (area / width) (4R ² / 2R) π / 2 = 1.57 times , and this, in turn, allows you to increase the cuvette with the test volume, while maintaining the dimensions of the system, making the DTM more efficient and convenient (especially the portable version).

Estimation of the resolution value of a HMC with a hemispherical matrix.

Due to the fact that the Rayleygh criterion is determined empirically for optical devices, in order to remove the dependence on the subjectivity of perception (two adjacent points are allowed if the minimum intensity between them is small enough to make it out), then the expression of resolution according to this criterion (1) has a different look. For example: the coefficient k can have a different value depending on the size and shape of the matrix of the optical system, namely, if the shape is round, then it is 1.22, if square - 1, if hemisphere - 0.63, because the larger the size of the matrix, the higher the resolution, all other things being equal.

Therefore, it is possible to determine the resolution for a HMC with a hemispherical matrix by the formula (1).

Given (see Figure 2) that k = 0.63; λ = 0.488 μm (Ar laser), f / D = 0.312, then according to expression (1) R = kλf / D, we obtain the following resolution

R = 0.63 × 0.488 × 0.312 = 0.095 μm.

Thus, the resolution of a HMC with a hemispherical matrix of 95 nm was obtained without the use of special mathematical processing.

Thus, in this application proposed the following design solutions using:

1) a filter to smooth the Gaussian distribution of the beam of the radiation source in order to increase the aperture ratio of the peripheral pattern of interference bands recorded on the matrix;

2) a hemispherical matrix, allowing:

- register high-frequency interference hologram bands that determine the high resolution of the reconstructed image;

- create a compact system TsGM;

- increase the volume with the investigated object.

LITERATURE

1. Turukhano B.G. Accumulation of information on the hologram by the depth of the reconstructed image and loading of the bubble chamber with tracks. ZhTF, vol. 90, No. 1, p. 181-187, vol. 1970.

2. MATLAB Advisory Center SoftLine company http://www.nose.ru/matlab/Mata_RU/default.asp.hum.

3. The program for restoring holographically recorded images and determining the spatial location of point objects "Digital Holography" ”. RF patent №2009614972 from 09/11/2009.

4. Aloon Greenbaum, Aydogan Ozkan. Increased space-bandwidth product in pixel super-resolved lensfree on-chip microscopy. Scientific Reports, published 24 April, 2013.

5. Tomoyoshi Shimobaba, Nobuyuki Masuda and Tomoyoshi Ito. Multi-view and multi-resolution real-time digital holographic microscopy. Microscopy: Science, Technology, Application and Education, pp. 1419-1425, 2010.

6. D. Gabor. A new microscopic principle. Nature 161, pp. 777-778, 1948.

7. S.K. Jericho, P. Klages, J. Nadeau, E.M. Dumas, M.H. Jericho, H.J. Kreuzer. In-line digital holographic microscopy for terrestrial and exobiological research. Planetary and Space Science 58, pp. 701-705, 2009.

8. Ulf Schnars and W PO Juptner. Digital recording and numerical reconstruction of holograms. Meas. Sci. Technol., 13, R85-R101, 2002.

Claims (1)

A digital holographic microscope containing a radiation source having an optical axis directed towards the propagation of the radiation beam, a focusing lens, an aperture, and a cuvette for placing the object under study, located along the optical axis, the cuvette having transparent input and output windows, and the input window is flat, the matrix photodetectors, an electronic computer system including a processing unit, software and a PC, characterized in that in addition to the cuvette a smoothing filter is introduced Gaussian distribution of the radiation beam and obtaining uniform illumination over the beam cross section, the output window of the cell has a hemisphere shape with a radius equal to the distance from the input to the output window of the cell, and the photodetector array has the shape of a hemisphere, is parallel to the output window of the cell, repeats its shape and is rigid with it connected.

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