Device for controlling photoreceptor cell movement based on vector light field

Abstract

The present invention discloses a device for regulating photoreceptor cell movement based on a vector light field. The device includes a collimated light source, a linear polarizer, a first quarter-wave plate, a reflective spatial light modulator, a second quarter-wave plate, a beam expander, a stage, and a spectrometer. A first beam of light emitted directly from the spectrometer passes through a telecentric lens and enters a first camera, which is then connected to a computer. A second beam of light reflected from the spectrometer passes through a macro lens and enters a second camera, which is also connected to a computer. The spatial light modulator can generate a vector light field with arbitrary polarization directions within any x-y plane. By applying this vector light field to a sample within a thin-sheet sample module, the motion direction of all individual photoreceptor cells within the sample can be modulated according to the input signal, thereby achieving functions such as aggregation and directional movement of the photoreceptors.

Description

Technical Field

[0001] The present invention relates to the field of microbial control, and in particular to a device for regulating the movement of photoreceptor cells based on a vector light field. Background Art

[0002] A vector light field refers to an optical electromagnetic field with a specific polarization distribution in the spatial domain. Typically, the propagation direction of a vector light field is called the z-axis, and different regions within the xy plane have different polarization states. φ(x,y,t) is defined as the polarization direction at point (x,y) in the plane at time t. Any single-valued function of φ(x,y,t) can represent a vector light field. Existing technology can generate arbitrary vector light fields by combining a spatial light modulator with a quarter-wave plate.

[0003] Photoreceptors are a common type of cell found in nature, encompassing a wide range of photosynthetic organisms, particularly microorganisms that can move freely in water, such as algae. These microorganisms are able to sense various characteristics of light, such as intensity, direction, wavelength, and polarization. Current microbial control technologies are limited to precisely controlling individual microorganisms or simply controlling groups of microorganisms, and struggle to precisely control the movement of all microorganisms within a given area.

[0004] Traditional commercial microscope technology is relatively mature, but it has disadvantages such as high price and small field of view. If you want to observe the movement of micron-scale microorganisms at the centimeter scale, traditional microscope systems are difficult to observe for a long time.

[0005] The disadvantage of CN113625459B is that the spatial distribution pattern of the vector light field is determined by the vortex half-wave plate, and can only generate rotationally symmetric vector light fields. The present invention can not only generate such light fields, but also arbitrarily customize the spatial distribution pattern of the vector light field, especially the vector light field with local discontinuous changes.

[0006] CN110849818A uses a liquid crystal phase retarder, so the light field in the device is uniform linearly polarized light, and spatial changes in the polarization direction cannot be achieved. Secondly, the invention uses a single camera to observe only one scale of imaging. The present invention can not only generate vector light fields with arbitrary spatial distribution, but also the dual optical paths can be observed simultaneously at two magnifications of 5X and 0.5X. Summary of the Invention

[0007] Based on this, in order to address the above problems, the present invention combines the technology of generating arbitrary vector light fields with spatial light modulators, regulates the movement of photoreceptor cells within the centimeter scale through vector light fields, and forms a set of splitting optical paths with telecentric lenses and macro lenses to simultaneously observe the overall and local regulation effects.

[0008] The technical solutions of the present invention are as follows:

[0009] A device for controlling photoreceptor cell movement based on a vector light field comprises a collimated light source, a linear polarizer, a first quarter-wave plate, a reflective spatial light modulator, a second quarter-wave plate, a beam expander, a stage, and a spectrometer. A first beam of light directed from the spectrometer passes through a telecentric lens and enters a first camera, which is then connected to a computer. A second beam of light reflected from the spectrometer passes through a macro lens and enters a second camera, which is then connected to a computer.

[0010] The real-time images displayed by the first camera and the second camera can be observed simultaneously on the computer.

[0011] The thin slice sample prepared from the photoreceptor cells is placed on the sample stage.

[0012] The chip of the spatial light modulator is rectangular, with its long side as the x-axis and the short side as the y-axis. The polarization direction of the linear polarizer is parallel to the x-axis. The collimated light source emits a light beam that passes through the linear polarizer to form linear polarized light with a polarization direction parallel to the x-axis.

[0013] The angle between the fast axis direction of the first quarter wave plate and the x-axis is 45 degrees, and the linearly polarized light is converted into circularly polarized light after passing through the first quarter wave plate.

[0014] The SLM chip has a resolution of 1920x1200 pixels and modulates the phase of the electromagnetic wave incident on each point. When circularly polarized light is reflected by the SLM chip, the phase of the reflected circularly polarized light at each point changes, with the amount of change controlled by the SLM's input signal.

[0015] The fast axis of the second quarter-wave plate is at an angle of 135 degrees to the x-axis. The circularly polarized light reflected from the spatial light modulator is converted into linearly polarized light after passing through the second quarter-wave plate. The polarization direction of each point is determined by the previous phase change value. Polarized light with different polarization directions at different locations in space forms a vector light field, which is further amplified by the beam expander to form a vector light field of approximately 20X20mm in size.

[0016] The light field acts on the thin sample, and the movement of the photoreceptor cells placed in it is regulated by the polarization direction of the light.

[0017] The light beam formed after the light field passes through the sample is divided into two beams by the spectrometer. The first beam is direct light, which is imaged onto the target surface of the first camera through a 0.5X telecentric lens. The movement of the photoreceptor cells in the sample under the action of the entire vector light field can be observed; the second beam is reflected light, which is imaged onto the target surface of the second camera through a 5X macro lens. The movement of local photoreceptor cells in the sample under the action of the vector light field can be observed.

[0018] The Jones matrix of the first quarter-wave plate is Where i is the imaginary unit

[0019] The Jones matrix of the second quarter-wave plate is

[0020] The Jones matrix of the reflective spatial light modulator is: Where φ represents the information input to the spatial light modulator. In a spatial light modulator with a resolution of 1920x1200, each pixel can be set to a different φ value.

[0021] The Jones matrix of the vector light field is

[0022]

[0023] The Jones matrix of the vector light field is equivalent to a rotation matrix with a rotation angle of φ / 2. Therefore, any vector light field can be obtained by rotating the linearly polarized light at each pixel point by a different φ / 2 angle.

[0024] The thin slice sample is made of two cover glasses, with photoreceptor cells and their culture solution placed in the middle, and double-sided tape is used to stick and separate the two cover glasses around them.

[0025] The telecentric lens has a magnification of 0.5X, which can reduce the field of view of 20x20mm to a range of 10x10mm, making it convenient to shoot and observe the overall movement of photoreceptor cells in the camera.

[0026] The macro lens has a magnification of 5X, which can magnify the field of view of the sample with a range of 2x2mm to a range of 10x10mm, making it convenient to shoot and observe the local movement of photoreceptor cells in the camera.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention can arbitrarily set a vector light field that changes in time and space, and observe samples from two scales under the action of the light field. For example, in a microbial sample added with tracer beads, the movement of the microorganisms can be observed at a large scale, and the movement of the tracer beads can be observed at a small scale to observe the flow field. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the device for regulating photoreceptor cell movement based on vector light field of the present invention.

[0030] Figure 2 This is the first vector light field distribution example of the present invention, with the polarization direction being

[0031] Figure 3 This is the second vector light field distribution example of the present invention, with the polarization direction being

[0032] Reference numerals

[0033] In the figure, 10 is a collimated light source, 11 is a linear polarizer, 12 is the first quarter-wave plate, 13 is a reflective spatial light modulator, 14 is a second quarter-wave plate, 15 is a beam expander, 16 is a reflector, 17 is a spectrometer, 21 is a stage, 22 is a photoreceptor cell slice sample, 30 is a 0.5X telecentric lens, 31 is the first camera, 40 is a 5X macro lens, and 41 is the second camera. DETAILED DESCRIPTION

[0034] In order to better illustrate the content of the present invention, the following is a detailed description with reference to the accompanying drawings and implementation examples.

[0035] In this example, Euglena gracilis is used as a photoreceptor cell. Euglena gracilis has the characteristic of aligning with the direction perpendicular to the polarization direction of light when moving.

[0036] In this embodiment, blue light with a wavelength of 470 nanometers, optimal for Euglena gracilis, is used. The beam diameter is greater than 30 mm. After passing through a linear polarizer 11, the collimated light source 10 becomes linearly polarized light, with its polarization direction parallel to the y-direction of the spatial light modulator. This linearly polarized light then passes through a vector light field generation module consisting of a first quarter-wave plate, spatial light modulator, and second quarter-wave plate (12-13-14). This vector light field is then amplified by a beam expander 15 and reflected by a reflector 16 onto a thin glass sample 22 on a sample stage 21.

[0037] In this embodiment, two vector light fields are used as demonstrations.

[0038] Example 1:

[0039] The polarization direction of the input linear polarized light is The input signal of the spatial light modulator is Therefore, the distribution of polarization directions in the vector light field is In this light field, the polarization direction has Figure 2 As shown in the directional distribution, under the action of this vector light field, the photoreceptor cells will gather to the central position.

[0040] Example 2:

[0041] The polarization direction of the input linear polarized light is The input signal of the spatial light modulator is Therefore, the distribution of polarization directions in the vector light field is In this light field, the polarization direction has Figure 3As shown in the directional distribution, under the action of this vector light field, the photoreceptor cells will rotate counterclockwise along a circular orbit with a radius of ρ = n*R / 2 (n is a positive integer).

[0042] The thin glass sample preparation process begins with cutting a 50-micron-thick double-sided tape into a ring with an inner diameter exceeding 30 mm. This is then affixed to a cover glass. The prepared Euglena liquid is then poured in, and another cover glass is affixed on top to create a closed thin glass sample.

[0043] The vector light field acts on the thin glass sample, regulating the movement of the delicate algae therein. The light beam is then split into two by a beam splitter, entering a telecentric lens 30 and a macro lens 40 respectively. The telecentric lens has a magnification of 0.5X, so a 20x20mm field of view can form a 10x10mm image on the camera, allowing observation of overall movement. The macro lens has a magnification of 5X, so a 2x2mm field of view can be magnified into a 10x10mm image on the camera, allowing observation of local movement.

[0044] In the local polarization direction of the vector light field Under the action of v , its angular velocity is modulated, which is expressed as Here A is the intensity of the modulation, which is related to the light intensity, and C is the rotational bias (chirality) of the slender algae. Under such modulation, Figure 2 The vector light field shown will gather the elliptical algae at the center. Figure 3 The vector light field shown will control the gracilis algae to rotate counterclockwise in a circular orbit with a radius of ρ = n*R / 2 (n is a positive integer).

Claims

1. A device for regulating photoreceptor cell movement based on a vector light field, characterized in that: The invention comprises a linear polarizer (11), a first quarter-wave plate (12), a reflective spatial light modulator (13), a second quarter-wave plate (14), a beam expander (15), a reflector (16), a stage (21) for placing a thin glass sample (22), and a beam splitter (17), which are sequentially arranged along the transmission direction of a collimated light source (10); the beam splitter (17) is divided into reflected light and transmitted light; the transmitted light enters a first camera through a telecentric lens (30) and is connected to a computer; the reflected light enters a second camera through a macro lens (40) and is connected to a computer; The Jones matrix of the reflective spatial light modulator is: Where φ represents the information input of the reflective spatial light modulator; the Jones matrix of the vector light field is 2. The device for controlling photoreceptor cell movement based on a vector light field according to claim 1, characterized in that: The chip of the reflective spatial light modulator (13) is rectangular, with the long side being the x-axis and the short side being the y-axis. The polarization direction of the linear polarizer is parallel to the x-axis, and the collimated light source emits a light beam passing through the linear polarizer to form linear polarized light with a polarization direction parallel to the x-axis.

3. The device for controlling photoreceptor cell movement based on a vector light field according to claim 1 or 2, characterized in that: The reflective spatial light modulator chip has a resolution of 1920x1200 and is capable of modulating the phase of the electromagnetic wave irradiating each point. After the circularly polarized light is reflected by the reflective spatial light modulator chip, the phase of the circularly polarized light reflected at each point will change, and the change value is controlled by the input signal of the reflective spatial light modulator.

4. The device for controlling photoreceptor cell movement based on a vector light field according to claim 1 or 2, characterized in that: The angle between the fast axis direction of the first quarter wave plate and the x-axis is 45 degrees, and the linearly polarized light is converted into circularly polarized light after passing through the first quarter wave plate.

5. The device for regulating photoreceptor cell movement based on vector light field according to claim 1 or 2, characterized in that: The fast axis of the second quarter-wave plate is at an angle of 135 degrees to the x-axis. The circularly polarized light reflected from the reflective spatial light modulator is converted into linearly polarized light after passing through the second quarter-wave plate. The polarization direction of each point is determined by the previous phase change value. Polarized light with different polarization directions at different locations in space forms a vector light field, which is further amplified by the beam expander to form a vector light field with a size of 20X20mm.

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