A light manipulation system for micron-sized particles

Abstract

This invention provides an optical manipulation system for micron-sized particles, comprising a laser, an optical system, and a sample stage. The laser beam generated by the laser is focused by the optical system onto a sample on the sample stage to control the rotation and revolution of the micron-sized particles within the sample. The optical system includes a convex lens assembly, a half-wave plate, a quarter-wave plate, a vortex half-wave plate, a reflecting mirror, and a semi-transparent mirror, sequentially arranged along the laser path. By precisely controlling each component of the light field, independent control of the rotation and revolution of micron-sized particles can be achieved, solving the problems of low degrees of freedom in particle motion control and complex experimental systems in existing technologies. This system offers high flexibility and broad application prospects.

Description

Technical Field

[0001] This utility model relates to the field of optical manipulation technology, and more specifically, to an optical manipulation system for micron-sized particles. Background Technology

[0002] Optical manipulation technology, which uses a single-beam focused laser to form an optical trap to capture tiny objects, offers advantages such as non-contact, non-destructive, and high precision, and is therefore widely used in physics, chemistry, and biomedicine. In recent years, with the development of structured light field technology, the spatial variation of amplitude, phase, and polarization in optical fields has attracted considerable attention. By manipulating the spatial modes of structured light fields, richer and more stable optical force distributions can be obtained, greatly enriching the manipulation capabilities of optical micro and nanoparticles. Structured light field-driven optical tweezers can overcome the shortcomings of traditional optical tweezers and further promote the development of optical particle manipulation technology.

[0003] In the field of optical particle manipulation, copper oxide (CuO) microparticles, as typical absorptive particles, exhibit rotational and revolving motion characteristics under the influence of structured light fields. By controlling the components of a higher-order Poincaré (HOP) light field, independent control of the rotation and revolution of micron-sized particles can be achieved, providing a new approach and technical solution for the precise manipulation of micro and nanoparticles. Compared with traditional optical manipulation techniques, particle manipulation systems based on HOP light fields offer greater flexibility and higher control precision, enabling precise adjustment of the rotational speed and direction of micron-sized particles, and have broad application prospects, especially in biomedicine, micromechanics, and optical classification.

[0004] Currently, most existing particle manipulation systems rely on traditional Gaussian optical tweezers technology, which has significant limitations in controlling the rotational direction and velocity of particles. Traditional systems typically require complex optical paths and multiple optical components during design and construction, and their functionality is relatively limited, failing to achieve flexible control over particle motion. Some existing technologies, such as patent application number 202110508932.7, propose a method for controlling the position of microspheres using a dual-beam optical trap. While this method can stably capture particles, it requires the introduction of additional probe beams and feedback control circuits, resulting in complex optical path design and strong environmental dependence. Its functionality is also limited to stable control of particle position, unable to achieve independent control of particle rotation and revolution.

[0005] In addition, the patent with application number 201710416321.3 proposed to realize the three-dimensional manipulation of low refractive index medium nanoparticles by using radial polarization vortex light field. Although this method can realize the control of particle motion trajectory and support the simultaneous capture of multiple particles, it has weak independent control over the rotation and revolution of particles, and the experimental equipment requirements are high, requiring the use of complex optical components such as oil immersion objective and spatial light modulator, which increases the complexity of experimental device and the difficulty of fabrication process.

[0006] Therefore, existing particle manipulation technologies generally face problems such as insufficient control precision, poor flexibility, and system complexity. Utility Model Content

[0007] In view of this, the present invention proposes an optical manipulation system for micron-sized particles to solve the problems existing in the prior art.

[0008] To achieve the above objectives, this invention proposes an optical manipulation system for micron-sized particles, comprising a laser, an optical system, and a sample stage; the laser generated by the laser is focused by the optical system onto the sample on the sample stage to control the rotation and revolution of the micron-sized particles in the sample; The optical system includes a convex lens assembly, a half-wave plate, a quarter-wave plate, a vortex half-wave plate, a mirror, and a semi-transparent mirror arranged sequentially in the laser path. The convex lens assembly is used to collimate the laser beam output from the laser and transmit it to the half-wave plate. The half-wave plate and the quarter-wave plate are used to form orthogonally circularly polarized light; The vortex half-wave plate is used to impart orbital angular momentum to the beam, forming a higher-order Poincaré beam that carries both spin angular momentum and orbital angular momentum. The reflector is used to change the direction of light beam propagation and direct the light beam toward the semi-transparent and semi-reflective mirror; The semi-transparent and semi-reflective mirror is used to further adjust the beam propagation direction so that the beam is perpendicular to the sample stage and illuminates the micron-sized particles in the sample.

[0009] In one embodiment, the system further includes an observation and recording component for observing and recording the motion of micron-sized particles; The observation and recording components include a CCD camera, a computer, a light source, a first objective lens, and a second objective lens; The first objective lens is disposed on the side of the sample stage away from the semi-transparent mirror, and the light source is disposed on the side of the first objective lens away from the sample stage. The first objective lens is used to focus the illumination beam of the light source and illuminate the sample. The second objective lens is disposed between the semi-transparent mirror and the sample stage. The CCD camera is located on the side of the semi-transparent mirror away from the mirror. The computer is electrically connected to the CCD camera and is used to record the motion of micron-sized particles.

[0010] In one embodiment, the convex lens assembly includes a first convex lens and a second convex lens, the first convex lens being disposed close to the laser and the second convex lens being disposed close to the half-wave plate; The first convex lens focuses the laser beam onto the focal point of the second convex lens.

[0011] In one embodiment, the topological order of the vortex half-wave plate is 2.

[0012] In one embodiment, the laser is a continuous laser with a wavelength of 0.64 nm and an output power of 65 mW.

[0013] In one embodiment, the micron-sized particles in the sample are irregular absorbing particles with a diameter in the range of 3-6 μm.

[0014] In one embodiment, the incident angle of the light beam passing through the semi-transparent mirror is perpendicular to the sample stage.

[0015] In one embodiment, the reflector is at a 45° angle to the light beam.

[0016] In one embodiment, the system includes a rotation mechanism connected to the half-wave plate for driving the half-wave plate to rotate, thereby changing the angle between the fast axis of the half-wave plate and the horizontal axis.

[0017] In one embodiment, the sample comprises CuO particles or polystyrene particles in a CuO solution.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: The micron particle motion control system provided by this invention can simultaneously and independently control the rotation speed and direction of rotation of micron particles, greatly improving the flexibility and precision of particle motion control and broadening its application range.

[0019] The system provided by this invention consists of a laser and an optical system. It uses a single-beam system to construct a HOP light field and generate the required optical force to manipulate micron particles. The structure is simple, easy to implement, and does not require complex additional optical components.

[0020] This invention has been verified to have the best effect through multiple experiments, providing reliable data support for further research and practical application, and providing a valid basis for the manufacture of particle motion control systems. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. In the drawings: Figure 1 This is a schematic diagram of the optical manipulation system for micron-sized particles in an embodiment of the present invention; Figure 2 This is a diagram showing the experimental results of CuO particle revolution observed under the microscopic imaging system in this embodiment of the invention; Figure 3 This is a diagram showing the experimental results of CuO particle rotation observed under the microscopic imaging system in this embodiment of the invention.

[0022] Reference numerals: 1. Laser; 2. First convex lens; 3. Second convex lens; 4. Half-wave plate; 5. Quarter-wave plate; 6. Vortex half-wave plate; 7. Mirror; 8. Semi-transparent and semi-reflective mirror; 9. CCD camera; 10. Computer; 11. Second objective lens; 12. Sample stage; 13. First objective lens; 14. Light source. Detailed Implementation

[0023] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] To address the technical problems in existing technologies, this embodiment proposes a system for independently controlling the rotation and revolution of micron-sized particles. By manipulating orthogonally polarized superimposed HOP light, adjusting the weights of each component of the HOP light field can change the total angular momentum of the light field, thereby independently controlling the rotational speed and direction of the micron-sized particles' rotation and revolution without affecting the spot size. This invention significantly improves the stability of micron-sized particle manipulation and provides flexible rotational speed control.

[0025] Reference Figure 1 This embodiment proposes an optical manipulation system for micron-sized particles, including a laser 1, an optical system, and a sample stage 12. The laser generated by the laser 1 is focused by the optical system onto the sample on the sample stage 12 to control the rotation and revolution of the micron-sized particles in the sample.

[0026] The optical system includes a convex lens assembly, a half-wave plate 4, a quarter-wave plate 5, a vortex half-wave plate 6, a reflector 7, and a semi-transparent mirror 8, sequentially arranged along the laser path. The convex lens assembly collimates the laser beam output from the laser 1 and transmits it to the half-wave plate 4; the half-wave plate 4 and the quarter-wave plate 5 form orthogonally circularly polarized light; the vortex half-wave plate 6 imparts orbital angular momentum to the beam, forming higher-order Poincaré light carrying both spin and orbital angular momentum; the reflector 7 changes the beam propagation direction and directs the beam towards the semi-transparent mirror 8; the semi-transparent mirror 8 further adjusts the beam propagation direction, making the beam perpendicular to the sample stage 12 and illuminating the micron-sized particles in the sample.

[0027] It should be noted that the angle between the fast axis and the horizontal axis of half-wave plate 4 is adjustable, thereby controlling the polarization characteristics of the HOP beam. By adjusting this angle, the total angular momentum of the light field can be flexibly controlled, thus achieving independent control of the particle's rotation and revolution.

[0028] In this embodiment, the laser 1 used has a wavelength of 1064 nm and an output power of 65 mW, and the topological charge of the vortex half-wave plate 6 is 2. After passing through the optical system, the laser beam finally irradiates the CuO solution on the sample stage 12, and the particles rotate and revolve under the photodynamic force generated by the HOP light field.

[0029] When the sample is CuO microparticles, due to the metal oxide properties of CuO microparticles, they absorb some light, enhance the scattering force, and reduce the gradient force, thereby enabling the visualization of the rotation (dependent on spin angular momentum) and revolution (dependent on orbital angular momentum) phenomena.

[0030] The method for independently controlling the rotation and revolution of particles is as follows: The beam emitted by laser 1 is formed into a circular Gaussian beam by a convex lens group, and then passes through a half-wave plate 4 and a quarter-wave plate 5 to form orthogonally circularly polarized light. After passing through a vortex half-wave plate, the beam gains orbital angular momentum to form HOP light, which changes its propagation direction after passing through a reflector and finally illuminates the sample stage. Under the action of the HOP light field, the particles rotate and revolve. Adjusting the angle between the half-wave plate and the horizontal axis allows for independent control of the rotation and revolution speed and direction of the particles.

[0031] In the above embodiment, the horizontally linearly polarized beam emitted from laser 1, after being collimated by a convex lens assembly, passes sequentially through a half-wave plate 4 with a fast axis angle of α and a quarter-wave plate 5 with a fast axis angle of 45°. The output beam form can be represented by a Jones matrix:

[0032] The three Jones vectors, from left to right, represent horizontally polarized light, left-handed circularly polarized light, and right-handed circularly polarized light, respectively. It can be seen that the linearly polarized light, after passing through half-wave plate 4 and quarter-wave plate 5, forms superimposed orthogonally circularly polarized light. The beam then further passes through a vortex half-wave plate 6 of order m, causing the orthogonally circularly polarized beam to carry orbital angular momentum, which can be expressed as:

[0033] As can be seen, after passing through a vortex half-wave plate of order m, the left-hand circularly polarized light becomes right-hand circularly polarized light and carries an orbital angular momentum of order m, while the right-hand circularly polarized light becomes left-hand circularly polarized light and carries an orbital angular momentum of order -m, thus forming HOP light.

[0034] in and These are the controllable optical field profile parameters of the HOP light, i.e., the weighted components of the HOP, which can be controlled by the fast axis angle α of the half-wave plate. The fast axis angle is defined as the angle between the fast axis and the horizontal axis.

[0035] This embodiment of the micron-particle manipulation system utilizes the optical force generated by momentum exchange during the interaction of laser light with matter to control the motion of micron-particles. By adjusting the weights A and B of each component of the HOP optical field, the rotation and revolution speeds and directions of the micron-particles can be effectively and independently controlled, thereby improving manipulation precision and stability. This system is not only applicable to CuO microparticles but can also be extended to other types of microparticles, such as polystyrene microparticles.

[0036] This system uses two orthogonally conjugate circularly polarized Laguerre-Gauss beams with opposite topological charges to form a high-amplitude (HOP) beam. By adjusting the weights of each component of the HOP optical field, independent control of the rotation and revolution of micron-sized particles can be achieved. By adjusting the fast axis angle of the half-wave plate in the optical system, the total angular momentum of the HOP optical field is changed, thereby enabling independent control of the rotational speed and direction of the micron-sized particles' rotation and revolution.

[0037] Specifically, when the fast axis angle of the half-wave plate is less than 22.5°, the total angular momentum is in the positive direction, which allows the particle to revolve clockwise around the optical axis at a relatively high speed, while the particle spins counterclockwise around its own axis at a relatively low speed. When the included angle is 22.5°, the total angular momentum is zero, and the particle stops rotating. When the included angle is greater than 22.5°, the total angular momentum is in the negative direction, which allows the particle to revolve counterclockwise around the optical axis at a relatively low speed, while the particle spins clockwise around its own axis at a relatively high speed.

[0038] To achieve independent control of the rotation and revolution of micron-sized particles, this invention employs a vortex half-wave plate with a topological charge of 2, which imparts orbital angular momentum to the light beam. The light beam is collimated by a convex lens group and then imbued with orbital angular momentum by the vortex half-wave plate to form HOP light. After being reflected by a mirror, it illuminates the particles on the sample stage. The rotational speed and direction of the particles are controlled by adjusting the angle between the fast axis and the horizontal axis of the half-wave plate. A quartz glass slide is placed on the sample stage 12, and the CuO particle solution sample is located on the quartz glass slide, which is positioned at the focal plane of the second objective lens.

[0039] In some embodiments, the system further includes an observation and recording component for observing and recording the motion of micron-sized particles; the observation and recording component includes a CCD camera 9, a computer 10, a light source 14, a first objective lens 13, and a second objective lens 11; the first objective lens 13 has a magnification of 10x, and the second objective lens 11 has a magnification of 20x.

[0040] The first objective lens 13 is positioned on the side of the sample stage 12 away from the semi-transparent mirror 8, and the light source 14 is positioned on the side of the first objective lens 13 away from the sample stage 12. The first objective lens 13 is used to focus the illumination beam of the light source 14 and illuminate the sample.

[0041] The second objective lens 11 is positioned between the semi-transparent mirror 8 and the sample stage 12. The CCD camera 9 is located on the side of the semi-transparent mirror 8 away from the mirror 7. The computer 10 is electrically connected to the CCD camera 9 and is used to record the movement of micron-sized particles.

[0042] In some embodiments, the convex lens assembly includes a first convex lens 2 and a second convex lens 3. The first convex lens 2 is disposed near the laser 1, and the second convex lens 3 is disposed near the half-wave plate 4. The first convex lens 2 focuses the laser beam onto the focal point of the second convex lens 3. The distance between the laser 1 and the first convex lens 2 is greater than the distance between the first convex lens 2 and the second convex lens 3, which is used to collimate the beam output by the laser.

[0043] Specifically, the laser beam is collimated by the first convex lens 2 and the second convex lens 3, and then forms orthogonally circularly polarized light through the half-wave plate 4 and the quarter-wave plate 5. After passing through the vortex half-wave plate 6, the beam gains orbital angular momentum. After passing through the reflector, the direction of light propagation is perpendicular to the sample stage 12, illuminating the CuO particle sample. The resulting optical force causes the particles to rotate and revolve.

[0044] In some embodiments, the topological order of the vortex half-wave plate 6 is 2.

[0045] In some embodiments, laser 1 is a continuous laser with a wavelength of 1064 nm and an output power of 65 mW.

[0046] In some embodiments, the micron-sized particles in the sample are irregular absorbing particles with a diameter in the range of 3-6 μm.

[0047] In some embodiments, the incident angle of the light beam passing through the semi-transparent mirror 8 is perpendicular to the sample stage 12.

[0048] In some embodiments, the reflector 7 is at a 45° angle to the light beam.

[0049] In some embodiments, the system includes a rotating mechanism connected to the half-wave plate 4, which drives the half-wave plate 4 to rotate, thereby changing the angle between the fast axis of the half-wave plate 4 and the horizontal axis.

[0050] In some embodiments, the sample comprises CuO particles or polystyrene particles in a CuO solution. The CuO particles are ellipsoidal in shape and, being metal oxides, absorb some light; in this case, the direction of their orbital angular momentum affects their motion.

[0051] This invention also provides a control method for an optical manipulation system for micron-sized particles. The method includes: a laser beam emitted by a laser is collimated by a convex lens assembly, then passes sequentially through a half-wave plate and a quarter-wave plate to obtain orthogonally circularly polarized light, and after passing through a vortex half-wave plate, the beam acquires orbital angular momentum to form a higher-order Poincaré beam; by adjusting the angle between the fast axis of the half-wave plate and the horizontal direction, the controllable optical field profile parameters (left-hand circular component and right-hand circular component) of two orthogonally conjugate circularly polarized Laguerre-Gauss beams with opposite topological charges used to synthesize the higher-order Poincaré beam are adjusted, thereby realizing the control of the rotation and revolution of micron-sized particles and flexibly manipulating the rotation direction and speed of the particles.

[0052] This method enables independent control of the rotation speed and direction of micron-sized particles' rotation and revolution, further improving the precision and flexibility of particle manipulation.

[0053] The experimental operation using the system for optical manipulation of micron-sized particles described in the above embodiments is as follows: The CuO particles have a diameter of 3-6 μm. Before the experiment, a small amount of CuO solution is dropped onto a clean quartz glass slide and placed in a petri dish. The light beam is collimated and focused onto the sample stage by an optical system. The particles experience forces in the HOP light field, resulting in rotation and revolution. The weights of the light field components are changed by adjusting the angle of half-wave plate 4, thereby controlling the rotation and revolution speeds and directions of the particles.

[0054] In the experiment, the rotation of the particles could be controlled by adjusting the weights of the HOP light field components. For example, when the angle between the half-wave plate and the horizontal axis was adjusted to 2.5°, the particles revolved clockwise at a speed of 4.45 rad / s; when the angle was adjusted to 42.5°, the particles revolved counterclockwise at the same speed; and when the angle was 22.5°, the particles stopped rotating. By adjusting the weights of the polarization components, precise control of the particles' rotation and revolution could be achieved.

[0055] To verify the feasibility of this system, the inventors conducted relevant experiments: In the experiment, CuO particle samples were first prepared, and the output power of the laser was adjusted to 65mW. The incident angle of the beam illuminating the particles was adjusted by adjusting the tilt of the incident mirror. In this embodiment, the incident angle was 90° to the horizontal plane. Figure 2 The figure shows the rotational speed and direction of the particle's rotation and revolution under different HOP light field component weights. The arrows in the figure represent the particle's trajectory.

[0056] Figure 2 Figure (a) shows that when the angle between the half-wave plate and the horizontal axis is 2.5°, the particle revolves clockwise at a speed of 4.45 rad / s. Figure 2 Figure (b) shows that when the angle between the half-wave plate and the horizontal axis is 42.5°, the particle revolves counterclockwise at a speed of 4.45 rad / s. Figure 2 Figure (c) shows that the particle stops rotating when the angle between the half-wave plate and the horizontal axis is 22.5°. In the experiment, when the weight of the right-handed polarization component is greater, the total orbital angular momentum is positive, corresponding to... Figure 2 (a) The particle motion state; when the weight of the left-handed polarization component is larger, the total orbital angular momentum is negative, corresponding to Figure 2 (b) The particle motion state; when the weights of the two beam components are equal, the total orbital angular momentum is zero, corresponding to Figure 2 (c) shows the stationary state of the particles. By adjusting the weight of the polarization component in the HOP light field, the total orbital angular momentum (orbital angular momentum) of the light field is changed, thereby achieving precise control over the orbital direction and rotational speed of the particles.

[0057] In the experiment, the light beam carries spin angular momentum. When CuO particles are placed in the HOP beam, the spin angular momentum of the beam is transferred to the particles, causing them to rotate around their own axis. Due to the strong absorption characteristics of CuO particles, the scattering force of the particles is enhanced, and the gradient force is reduced, thus making the contribution of spin angular momentum to the particle rotation more significant. Figure 3 As shown, Figure 3 (a) Figure shows that when the half-wave plate makes an angle of 2.5° with the horizontal axis, the right-handed polarization component has a larger weight, the total spin angular momentum is positive, and the particle rotates counterclockwise; Figure 3(b) The figure shows that when the half-wave plate makes an angle of 42.5° with the horizontal axis, the left-handed polarization component has a larger weight, the total spin angular momentum is negative, and the particle rotates clockwise. Figure 3 Figure (c) shows that when the angle between the half-wave plate and the horizontal axis is 22.5°, the total spin angular momentum is zero and the particles are stationary. By adjusting the angle between the half-wave plate and the horizontal axis, the intensity of the spin angular momentum can be flexibly controlled, thereby regulating the rotation speed and direction of the CuO particles.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A system for optical manipulation of microparticles, characterized by, It includes a laser (1), an optical system and a sample stage (12); the laser generated by the laser (1) is focused by the optical system onto the sample on the sample stage (12) to control the rotation and revolution of micron particles in the sample; The optical system includes a convex lens assembly, a half-wave plate (4), a quarter-wave plate (5), a vortex half-wave plate (6), a reflector (7), and a semi-transparent and semi-reflective mirror (8) arranged sequentially on the laser path. The convex lens assembly is used to collimate the beam output by the laser (1) and transmit it to the half-wave plate (4). The half-wave plate (4) and the quarter-wave plate (5) are used to form orthogonally circularly polarized light; The vortex half-wave plate (6) is used to impart orbital angular momentum to the beam to form a higher-order Poincaré beam that carries both spin angular momentum and orbital angular momentum. The reflector (7) is used to change the direction of the light beam propagation and direct the light beam toward the semi-transparent and semi-reflective mirror (8). The semi-transparent and semi-reflective mirror (8) is used to further adjust the direction of beam propagation so that the beam is perpendicular to the sample stage (12) and irradiates the micron particles in the sample.

2. The optical manipulation system for microparticles according to claim 1, wherein, The system also includes an observation and recording component for observing and recording the movement of micron-sized particles; The observation and recording components include a CCD camera (9), a computer (10), a light source (14), a first objective lens (13), and a second objective lens (11). The first objective lens (13) is disposed on the side of the sample stage (12) away from the semi-transparent mirror (8), and the light source (14) is disposed on the side of the first objective lens (13) away from the sample stage (12). The first objective lens (13) is used to focus the illumination beam of the light source (14) and illuminate the sample. The second objective lens (11) is disposed between the semi-transparent mirror (8) and the sample stage (12). The CCD camera (9) is located on the side of the semi-transparent mirror (8) away from the mirror (7). The computer (10) is electrically connected to the CCD camera (9) for recording the movement of micron particles.

3. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The convex lens assembly includes a first convex lens (2) and a second convex lens (3), wherein the first convex lens (2) is disposed close to the laser (1) and the second convex lens (3) is disposed close to the half-wave plate (4); The first convex lens (2) focuses the laser beam onto the focal point of the second convex lens (3).

4. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The topological order of the vortex half-wave plate (6) is 2.

5. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The laser (1) is a continuous laser with a wavelength of 1064nm and an output power of 65mW.

6. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The micron-sized particles in the sample are irregular absorbing particles with a diameter ranging from 3 to 6 μm.

7. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The incident angle of the light beam passing through the semi-transparent mirror (8) is perpendicular to the sample stage (12).

8. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The reflector (7) is at a 45° angle to the light beam.

9. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The system includes a rotating mechanism connected to the half-wave plate (4) for driving the half-wave plate (4) to rotate, thereby changing the angle between the fast axis of the half-wave plate (4) and the horizontal axis.

10. The optical manipulation system for micron-sized particles according to claim 1, characterized in that, The sample includes CuO particles or polystyrene particles in a CuO solution.

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