CN217059955U

CN217059955U - Phase recovery data acquisition system based on corner-cube prism

Info

Publication number: CN217059955U
Application number: CN202220577069.0U
Authority: CN
Inventors: 程鸿; 李菊; 孙思维; 程一凡
Original assignee: Anhui University
Current assignee: Anhui University
Priority date: 2022-03-16
Filing date: 2022-03-16
Publication date: 2022-07-26
Anticipated expiration: 2032-03-16

Abstract

The utility model relates to a phase place resumes data acquisition system based on corner cube prism, including light source, collimating lens, double lens unit and camera unit. The two-lens unit includes a first imaging lens having a focal length f1 and a second imaging lens having a focal length f 2. The photographing unit includes a beam splitter, a mirror, a corner cube prism, a CCD camera, and a translation stage. The light source, the collimating lens, the first imaging lens, the second imaging lens, the beam splitter and the pyramid prism are sequentially arranged from left to right. The collimating lens, the first imaging lens and the second imaging lens are coaxially arranged. The pyramid prism is installed on the translation platform. The reflecting mirror is positioned on the light path of the light reflected by the beam splitter, and the pyramid prism is positioned on the light path of the light transmitted by the beam splitter. The utility model discloses can solve the not enough of prior art, reduce mechanical error, realize the collection of same time intensity image, and need not the secondary and change the device, easy operation is convenient.

Description

Phase recovery data acquisition system based on corner-cube prism

Technical Field

The utility model relates to an optical imaging phase place resumes technical field, concretely relates to phase place resumes data acquisition system based on corner cube prism.

Background

In the optical field, a complete light field information contains both intensity and phase, which can be fully described by a two-dimensional complex amplitude function.

U(x,y)＝A(x,y)e ^jφ(x,y)

When the light wave passes through the sample, both the intensity information and the phase information of the sample are included in the transmitted light. Studies have shown that about three quarters of the information is stored in the phase, while only one quarter of the information is stored in the amplitude. Therefore, phase estimation (recovery) from the intensity distribution of the sample, i.e., the phase recovery problem, has attracted a wide attention.

The amplitude of the object light wave can be directly acquired by the camera, but the phase cannot be directly detected. The most classical phase measurement method is interferometry, however this method suffers from the following disadvantages:

(1) the light waves enter the sensor area along different independent paths, and the measurement result is seriously damaged (caused by environmental interference) under the influence of vibration;

(2) the temporal coherence requirements of the light source are high, requiring relatively complex interference devices, etc.

Another very important class of non-interferometric phase measurement techniques is known as phase recovery techniques. The methods of phase recovery are mainly divided into two categories: iterative methods and intensity transfer equation methods. Compared with an iterative method, the intensity transmission equation method has great advantages, a complex interference device is not required to be introduced, and the phase distribution of the object can be rapidly and accurately solved through the relation between the intensity and the phase distribution of the object in optical propagation. Meanwhile, the intensity transmission equation method can be well applied to the traditional bright field microscope imaging.

The intensity transfer equation expression is as follows:

wherein the light wave propagates along the z-direction, λ represents the wavelength of the light, I and

respectively represent z ₀ The intensity and phase of the location. In this equation, the partial derivative of the intensity in the z direction is difficult to calculate, and is usually approximated by acquiring multiple intensity images. For example, z may be adopted ₀ + Δ z and z ₀ The intensity information of the Δ z position is obtained by the following difference calculation formula:

the existing phase retrieval method based on TIE needs to move a object or a CCD when acquiring a light intensity image, which introduces unnecessary mechanical errors and cannot acquire an intensity image at the same time. Moreover, a hardware optical path system of the conventional phase recovery data acquisition system can realize more groups of measurement results only by replacing devices for the second time, and the operation is complicated.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a phase place resumes data acquisition system based on corner cube prism, this system can solve the not enough of prior art, reduces mechanical error, realizes the collection of same time intensity image, and need not the secondary and change the device, and easy operation is convenient.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a phase recovery data acquisition system based on a corner-cube prism comprises a light source, a collimating lens, a double-lens unit and a camera unit.

The double-lens unit comprises a first imaging lens with a focal length of f1 and a second imaging lens with a focal length of f 2; the photographing unit includes a beam splitter, a reflector, a cube-corner prism, a CCD camera, and a translation stage.

The light source, the collimating lens, the first imaging lens, the second imaging lens, the beam splitter and the pyramid prism are sequentially arranged from left to right, and the collimating lens, the first imaging lens and the second imaging lens are coaxially arranged. The pyramid prism is installed on the translation platform. The center of the light source, the center of the first imaging lens and the center of the second imaging lens are on the same horizontal line.

Further, the light source is a point-like white light source.

Further, the collimating lens and the first imaging lens are used for placing a test sample.

Furthermore, the reflecting mirror is positioned on the light path of the light reflected by the beam splitter, and the pyramid prism is positioned on the light path of the light transmitted by the beam splitter. The CCD camera and the mirror, as well as the beam splitter, are at more or less the same horizontal position. In an actual experiment, the reflecting mirror is located at the position of the light reflected by the receiving beam splitter, the pyramid prism is located at the position of the light directly transmitted by the receiving beam splitter, and the spatial coordinates are used for explaining that the beam splitter is located at the original point, the pyramid prism is located in the positive east direction, the reflecting mirror is located in the positive west direction, and the CCD camera is located in the positive north direction.

Further, the distance from the test sample to the center of the first imaging lens is f1, the distance from the center of the first imaging lens to the back focal plane of the first imaging lens is f1, the distance from the back focal plane of the first imaging lens to the center of the second imaging lens is f2, and the sum of the distance from the center of the second imaging lens to the center of the beam splitter plus the distance from the center of the beam splitter to the center of the mirror plus the distance from the center of the mirror to the lens of the CCD camera is f 2.

Furthermore, the translation stage adopts a large constant photoelectric GCM-T series precision translation stage, the model of which is GCM-T25M 2L.

Furthermore, the light source, the collimating lens, the first imaging lens, the second imaging lens, the test sample and the CCD camera are respectively arranged on an optical test operating platform through a bracket, and the translation platform is arranged on the optical test operating platform.

According to the technical scheme provided by the utility model, the utility model discloses according to pyramid prism's parallel reflection characteristic, not only can transversely stagger two bundles of light that separate, can also guarantee that the upper and lower propagation distance of single bundle of light equals, need not make pyramid prism's mirror plane strictly perpendicular with the light path, also need not remove the CCD camera and can gather and be used for intensity transmission equation method to carry out two required images of phase retrieval, it is simple to have a design, and the cost is lower, to advantages and characteristics such as the resistance height of experimental error.

Drawings

Fig. 1 is a working principle diagram of the present invention.

Wherein:

1. the device comprises a white light source, 2, a collimating lens, 3, a test sample, 4, a double-lens unit, 41, a first imaging lens, 42, a second imaging lens, 5, a photographic unit, 51, a CCD camera, 52, a translation stage, 53, a pyramid prism, 54, a beam splitter, 55 and a reflector.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings:

a phase recovery data acquisition system based on corner-cube prism as shown in fig. 1 includes a light source 1, a collimating lens 2, a double lens unit 4 and a camera unit 5.

The two-lens unit 4 includes a first imaging lens 41 having a focal length f1 and a second imaging lens 42 having a focal length f 2; the photographing unit 5 includes a beam splitter 54, a mirror 55, a corner cube 53, a CCD camera 51, and a translation stage 52. The CCD camera is provided with a control device for controlling the CCD camera to shoot images. The utility model discloses a set up the pyramid prism at the rear side of beam splitter and speculum, can compensate the unable not enough of gathering same time intensity picture of traditional phase retrieval data acquisition, can gather two intensity pictures simultaneously in once exposing, through installing the pyramid prism on the translation bench in addition, can adjust the position of pyramid prism, do not need the secondary to change the measuring result that the device just can realize more multiunit, easy operation is convenient.

The light source 1, the collimating lens 2, the first imaging lens 41, the second imaging lens 42, the beam splitter 54 and the corner cube 53 are sequentially arranged from left to right, and the collimating lens 2, the first imaging lens 41 and the second imaging lens 42 are coaxially arranged. The corner cube 53 is mounted on a translation stage 52. The center of the light source 1, the center of the first imaging lens 41 and the center of the second imaging lens 42 are on the same horizontal line.

Further, the light source 1 is a point-like white light source.

Further, the collimating lens 2 and the first imaging lens 41 are used for placing the test sample 3.

Further, the mirror 55 is located on the light path reflected by the beam splitter 54, and the corner cube 53 is located on the light path transmitted by the beam splitter 54. To illustrate with spatial coordinates, the beam splitter is at the origin, the corner cube prism is in the true east direction, the mirror is in the true west direction, and the CCD camera is in the true north direction. The mirror and the beam transmitted through the beam splitter are adjusted to be incident perpendicularly to the mirror and the beam splitter, and the CCD camera and the two beams transmitted through the beam splitter 54 are adjusted to be disposed perpendicularly. In the experiment process, the camera position is moved according to an imaging effect graph in the CCD camera, and the camera is perpendicular to the light beam if the image of the sample in the imaging graph is positioned in the center of the visual field and is not inclined.

Further, in order to enable the 4f system to image accurately, the distance from the test sample 3 to the center of the first imaging lens 41 is adjusted to be f1, the distance from the center of the first imaging lens 41 to the back focal plane of the first imaging lens 41 is adjusted to be f1, the distance from the back focal plane of the first imaging lens 41 to the center of the second imaging lens 42 is adjusted to be f2, and the sum of the distance from the center of the second imaging lens 42 to the center of the beam splitter 54 plus the distance from the center of the beam splitter 54 to the center of the mirror plus the distance from the center of the mirror 55 to the lens of the CCD camera 51 is f 2.

Further, the translation stage 52 is mounted on an optical test bench. The translation stage 52 adopts a large constant photoelectric GCM-T series precision translation stage, the model of which is GCM-T25M 2L. Translation stage 52 may cause the corner cube to move linearly. The translation stage 52 includes a moving stage, a fixed stage, a sliding guide and a micrometer screw, and the corner cube prism 53 is installed on the moving stage. The micrometer screw rod is screwed to push the movable platform and the fixed platform to move relatively, and a sliding guide rail arranged in the translation platform ensures that the movable platform and the fixed platform move linearly relatively.

Further, the light source 1, the collimating lens 2, the first imaging lens 41, the second imaging lens 42, the test sample 3, and the CCD camera 51 are respectively mounted on the optical test operating platform through a bracket. The support comprises a support main body and cylindrical connecting pieces with external threads, wherein the cylindrical connecting pieces are arranged at two ends of the support main body, one cylindrical connecting piece is connected to an optical test operating platform, and the other cylindrical connecting piece is connected to a light source 1, a collimating lens 2, an imaging lens I41, an imaging lens II 42, a test sample 3 or a CCD camera 51.

The distance between the point-like white light source and the center of the collimating lens is f0, and the collimating lens is used for adjusting the light path to be in a collimating state. The imaging lens I, the imaging lens II, the reflecting mirror and the corner cube prism form a 4f system. The pyramid prism, also called as a retroreflector, has three reflecting surfaces perpendicular to each other, and no matter how much the incident angle is, the reflected light is always parallel to the incident light, and the reflection angle is always kept at 180 degrees, so that the cube can be used for ensuring the reflection angle of 180 degrees under the condition that the prism cannot be accurately aligned, and reflection imaging is inverted and reversed. In order to ensure the general applicability of the utility model, the values of f0, f1 and f2 can be adjusted according to the experimental environment under the condition of satisfying the 4f system. The sum of the distance from the second imaging lens 42 to the corner cube 53 through the beam splitter 54 and the distance traveled inside the corner cube 53 plus the distance from the corner cube 53 to the CCD camera 51 after passing out of the corner cube 53 through the beam splitter 54 is f2+ Δ z (Δ z < < f 2). The pyramid prism is mounted on a translation stage 52, which is used for adjusting the propagation distance of the light beam from the second imaging lens 42 to the pyramid prism 53 through the beam splitter 54, and the light beam is reflected in the pyramid prism 53 and then reaches the CCD camera 51 through the beam splitter 54, that is, the size of Δ z is adjusted, so that a plurality of sets of defocused image data can be obtained.

The image of the sample to be measured irradiated by the light parallel light emitted by the light source enters the pyramid prism after passing through the imaging lens I, the imaging lens II and the beam splitter. The CCD camera is divided into two paths, one path is reflected to a reflecting lens by a beam splitter and finally imaged on the right side of the CCD camera, and the other path is imaged on the left side of the CCD camera after a certain amount of transverse displacement due to the reflection characteristic of the corner cube prism. The position of the pyramid prism is adjusted through the translation stage, the two paths are adjusted to focus, and then the reflecting mirror is moved backwards by a certain distance, so that two intensity images with different defocusing distances can be acquired in one exposure. The light emitted by the point-like white light source is divergent, and the light beam becomes parallel light after passing through the collimating lens. And the light bearing the sample information is distributed on the back focal plane of the imaging lens I in proportion to the Fourier transform of the sample through the imaging lens I, and the back focal plane of the imaging lens II is subjected to the Fourier inverse transform to be restored into a clear image of the original sample. The beam splitter can split a beam of parallel light into two beams, one beam is reflected out, the other beam is directly emitted out according to the original path, and the beam returns back in the original path after passing through the reflector.

Turning on a point-like white light source 1, changing a light beam into a parallel light beam by using a collimating lens 2, wherein the parallel light beam passes through a test sample 3, an imaging lens 41 and an imaging lens 42 to a beam splitter 54, is divided into two parallel light beams by the beam splitter 54, one parallel light beam reaches a reflector 55, reaches a CCD camera 51 after being reflected by the reflector 55, and a CCD camera 51 shoots an intensity image of the test sample 3, namely a focusing intensity image required in phase recovery by using an intensity transmission equation method; the other beam of parallel light reaches the pyramid prism 53, and reaches the CCD camera 51 after being reflected by the pyramid prism 53, and the CCD camera 51 captures an intensity map of the test sample 3, that is, a defocus intensity map required for phase recovery by the intensity transmission equation method. The beam splitter is characterized in that light is split into two beams, a reflector and a pyramid prism are arranged at the corresponding position of the beam splitter, and the position is adjusted according to the imaging in the CCD camera.

To sum up, the utility model discloses according to the parallel reflection characteristic of pyramid prism, can not only transversely stagger two bundles of light that separate, can also guarantee that the upper and lower propagation distance of single bundle of light equals, need not make pyramid prism plane and light path strict verticality, also need not remove the CCD camera, can gather and be used for intensity transmission equation method to carry out the required two images of phase retrieval. The utility model has the advantages and characteristics of the design is simple, and the cost is lower, to the high grade of resistance of experimental error.

The above-mentioned embodiments are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art without departing from the design spirit of the present invention should fall into the protection scope defined by the claims of the present invention.

Claims

1. The utility model provides a phase retrieval data acquisition system based on corner cube prism which characterized in that: comprises a light source, a collimating lens, a double-lens unit and a camera unit;

the double-lens unit comprises a first imaging lens with a focal length of f1 and a second imaging lens with a focal length of f 2; the photographing unit comprises a beam splitter, a reflector, a pyramid prism, a CCD camera and a translation stage;

the light source, the collimating lens, the first imaging lens, the second imaging lens, the beam splitter and the pyramid prism are sequentially arranged from left to right, and the collimating lens, the first imaging lens and the second imaging lens are coaxially arranged; the pyramid prism is arranged on the translation table; the reflecting mirror is positioned on the light path of the light reflected by the beam splitter, and the pyramid prism is positioned on the light path of the light transmitted by the beam splitter.

2. The corner cube based phase recovery data acquisition system of claim 1, wherein: the light source is a point-shaped white light source.

3. The corner cube based phase recovery data acquisition system of claim 1, wherein: and a test sample is placed between the collimating lens and the first imaging lens.

4. The system of claim 2, wherein the system further comprises: the distance from the test sample to the center of the first imaging lens is f1, the distance from the center of the first imaging lens to the back focal plane of the first imaging lens is f1, the distance from the back focal plane of the first imaging lens to the center of the second imaging lens is f2, and the sum of the distance from the center of the second imaging lens to the center of the beam splitter and the distance from the center of the beam splitter to the center of the reflector and the distance from the center of the reflector to the lens of the CCD camera is f 2.

5. The corner cube based phase recovery data acquisition system of claim 1, wherein: the translation stage adopts a large constant photoelectric GCM-T series precise translation stage, the model of which is GCM-T25M 2L.

6. The corner cube based phase recovery data acquisition system of claim 2, wherein: the light source, the collimating lens, the first imaging lens, the second imaging lens, the test sample and the CCD camera are respectively arranged on an optical test operating platform through a support, and the translation platform is arranged on the optical test operating platform.