Nonlinear optical tweezers based on time lens frequency spectrum change

Abstract

The invention belongs to the technical field of optical control, and particularly relates to nonlinear optical tweezers based on time lens frequency spectrum variation, which comprise a time lens module, a pulse compression module, a collimation and beam expansion module, a sampling imaging module and an illumination module, the time lens module outputs continuous light which is sequentially subjected to polarization control and secondary phase modulation, converts the continuous light into a linear chirped pulse light signal, performs power amplification on the linear chirped pulse light signal, performs pulse cutting and power amplification on the linear chirped pulse light signal, and outputs the linear chirped pulse light signal; the pulse compression module compresses the linear chirped pulse light signal output by the time lens module and outputs ultra-short compressed pulse light; the collimation and beam expansion module reflects the ultrashort compressed pulse light compressed by the pulse compression module into a light beam and then performs light beam scanning and light beam expansion to form ultrashort pulse light. According to the invention, the capturing force of particles can be improved, the control range of time can be prolonged, and a target can be observed and controlled for a longer time under low-damage operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical manipulation, and particularly relates to a non-linear optical tweezer based on the spectral change of a temporal lens. Background Art

[0002] The pulsed-light-based non-linear optical tweezer has been developed significantly. However, due to the deficiencies in the research of pulsed light sources, the application of non-linear optical tweezers still has certain limitations. Starting from the definition of pulsed light, it can be known that the influencing factors on non-linear pulsed optical tweezers include the pulse width, repetition frequency, average power, and peak power of the pulse. In 2010, J. Shane et al. used pulse shaping technology to study the influence of the variation of pulse widths in the range of 1.5 orders of magnitude on non-linear pulsed optical trapping through experiments and numerical simulations. The results showed that the pulse width had no effect on 780-nm silica microspheres. In 2015, D. Roy et al. demonstrated the superior role of high-repetition-rate pulse excitation in the trapping of dielectric nanoparticles, and they quantitatively estimated the combination of the repetition rate and peak power of the stable trap. M. Muramatsu and his collaborators studied the dynamics of nanoparticles in femtosecond laser trapping and demonstrated that the trapped polystyrene nanoparticles were repetitively ejected from the focus, and the ejection frequency gradually decreased with the increase in the pulse sequence interval.

[0003] Currently, the research on the pulse width, peak power, and average power of pulsed light is carried out within about 1 order of magnitude, while the research on the pulse repetition frequency is limited by the difficulty of adjusting the ultra-short pulsed light source by 1 order of magnitude. At present, the effect of the repetition frequency of ultra-fast pulses on the stable optical trapping of microparticles still remains uncertain. Therefore, it is very necessary to construct an optical tweezer system for ultra-short picosecond pulsed light beams using a tunable repetition-rate temporal lens to study the influence of the pulse repetition frequency on particle trapping. Summary of the Invention

[0004] The object of the present invention is to provide a non-linear optical tweezer based on the spectral change of a temporal lens, which can enhance the trapping force of particles, extend the time manipulation range, and observe and manipulate the target for a longer time under low-damage operation.

[0005] The technical solution adopted by the present invention is specifically as follows:

[0006] A non-linear optical tweezer based on the spectral change of a temporal lens, comprising a temporal lens module, a pulse compression module, a collimation and beam expansion module, a sampling imaging module, and an illumination module;

[0007] The temporal lens module is used to output continuous light that has successively passed through polarization control and quadratic phase modulation, convert the continuous light into a linearly chirped pulsed light signal and perform power amplification, and then perform pulse cutting and power amplification on the linearly chirped pulsed light signal and output it;

[0008] The pulse compression module is used to compress the linearly chirped pulsed optical signal output by the time lens module and output an ultrashort compressed pulsed light;

[0009] The collimating and beam expanding module is used to reflect the ultrashort compressed pulsed light compressed by the pulse compression module into a light beam, and then perform beam scanning and beam expansion to form an ultrashort pulsed light;

[0010] The sampling imaging module is used to capture particles with the ultrashort pulsed light, and divide the captured image into a near-infrared range light beam and a visible light range light beam for image capture;

[0011] The illumination module is used to illuminate the captured image.

[0012] Further, the time lens module includes a continuous light source, a polarization controller I, a phase modulator, a radio frequency signal generator, a pre-amplifier, a polarization controller II, an intensity modulator, a power amplifier, and an optical fiber port;

[0013] The continuous light source is used to output continuous light to the polarization controller I;

[0014] The polarization controller I is used to perform polarization control on the continuous light, and input the continuously light with adjusted polarization state into the phase modulator;

[0015] The radio frequency signal generator is used to emit a radio frequency signal;

[0016] The phase modulator receives the sine signal wave emitted by the radio frequency signal generator to perform quadratic phase modulation on the continuous light, and the continuously laser after phase modulation is converted into a linearly chirped pulse with a 10 GHz repetition frequency;

[0017] The pre-amplifier is used to amplify the power of the linearly chirped pulsed optical signal;

[0018] The intensity modulator is used to perform pulse cutting on the linearly chirped pulsed optical signal after power amplification by using the radio frequency signal that has been synchronized from the radio frequency signal generator;

[0019] The power amplifier is used to adjust the power amplification of the linearly chirped pulsed optical signal after cutting;

[0020] The optical fiber port is used to output the linearly chirped pulsed optical signal amplified by the power amplifier.

[0021] Further, the pulse compression module includes a spatial light collimator, a quarter-wave plate, a half-wave plate, a mirror I, a spatial grating I, a spatial grating II, a mirror II, a mirror III, a mirror IV, and a mirror V;

[0022] The spatial light collimator is used to perform spatial light collimation output on the laser beam output by the optical fiber port;

[0023] The quarter-wave plate is used to perform phase modulation on the polarization state of the incident light, causing the polarization direction of the light to change;

[0024] The half-wave plate rotates the polarization direction of the incident light by introducing a phase difference to match the polarization direction of the pulse compression grating pair;

[0025] The spatial grating 1 and the spatial grating 2 are used as a dispersion medium to achieve pulse width compression of the pulsed light, forming a spatial dispersion compression region;

[0026] The first mirror is used to reflect the beam with the adapted polarization state into the spatial dispersion compression region;

[0027] The second mirror is used to reflect the reflected beam back into the compression region for a second time to achieve secondary compression of the pulse width;

[0028] The third mirror, the fourth mirror, and the fifth mirror are used to reflect the beam after secondary compression to achieve the output of the ultrashort compressed pulsed light.

[0029] Furthermore, the collimating and beam expanding module includes a sixth mirror, a galvanometer scanner, a first beam expanding lens, and a second beam expanding lens;

[0030] The sixth mirror is used to reflect the ultrashort compressed pulsed light compressed by the pulse compression module into the collimating and beam expanding module;

[0031] The galvanometer scanner controls the beam scanning through the sampling imaging module;

[0032] The first beam expanding lens and the second beam expanding lens form a beam expander, and the beam expander is used to expand the ultrashort pulsed beam.

[0033] Furthermore, the sampling imaging module includes a seventh mirror, a first dichroic mirror, a capture objective lens, a second dichroic mirror, a long-pass filter, a first focusing lens, a near-infrared camera, a second focusing lens, a visible light camera, and a host computer;

[0034] The seventh mirror is used to reflect the expanded ultrashort pulsed beam and transmit it to the first dichroic mirror and then transmit through the first dichroic mirror into the capture objective lens;

[0035] The capture objective lens is used to capture particles and transmit the captured image back to the first dichroic mirror;

[0036] The second dichroic mirror is used to separate the captured image into a beam image in the near-infrared range and a beam image in the visible light range;

[0037] The long-pass filter is used to block the light shorter than the set cut-off wavelength in the near-infrared range beam image;

[0038] The focusing lens 1 is used to focus the beam image in the near-infrared range transmitted through the long-pass filter to the near-infrared camera for determining the capture point;

[0039] The focusing lens 2 is used to focus the beam in the visible light range to the visible light camera;

[0040] The visible light camera is used to capture and image the beam in the visible light range;

[0041] The host computer is used to collect and process the beam image in the near-infrared range and the beam image in the visible light range.

[0042] Furthermore, the illumination module includes a white light LED light source, a light homogenizing and beam expanding device, a mirror 8, and an illumination objective lens;

[0043] The white light LED light source is used to emit white light;

[0044] The light homogenizing and beam expanding device is used to homogenize and expand the white light;

[0045] The mirror 8 is used to reflect the white light processed by the light homogenizing and beam expanding device to the illumination objective lens;

[0046] The illumination objective lens is used to focus the white light onto the sample or target area to achieve uniform illumination for focused illumination.

[0047] The technical effects achieved by the present invention are as follows:

[0048] A non-linear optical tweezer based on the spectral change of a temporal lens according to the present invention introduces a temporal lens pulsed light source, which is used as an ultrashort pulsed beam to capture polystyrene fluorescent particles, and excites the optical Kerr effect in the particles, introducing a non-linear effect to realize a non-linear optical tweezer. Compared with the traditional optical tweezer, the range of the manipulation time can be extended, and the target can be observed and manipulated for a longer time under low-damage operation, thereby improving the biocompatibility between the optical tweezer system and the biological sample, and having a great application prospect. Description of the Drawings

[0049] Figure 1 It is the schematic diagram of the present invention.

[0050] Figure 2 It is the time domain diagram of different repetition rate ultrashort pulsed optical signals in the present invention.

[0051] Figure 3 It is the tunable ultrashort pulse width diagram in the present invention.

[0052] Figure 4 It is the linear relationship between the repetition rate and the capture force under the conditions of the same peak power and the same average power in the present invention.

[0053] In the attached drawings, the list of components represented by each reference numeral is as follows:

[0054] 101. Afterglow light source; 102. Polarization controller 1; 103. Phase modulator; 104. RF signal generator; 105. Preamplifier; 106. Polarization controller 2; 107. Intensity modulator; 108. Power amplifier; 109. Fiber optic port; 201. Spatial light collimator; 202. Quarter-wave plate; 203. Half-wave plate; 204. Mirror 1; 205. Spatial grating 1; 206. Spatial grating 2; 207. Mirror 2; 208. Mirror 3; 209. Mirror 4; 210. Mirror 5; 301. Mirror 6; 302. Galvanometer; 303. Beam expander 1; 304. Beam expander 2; 401. Mirror 7; 402. Dichroic mirror 1; 403. Capture objective lens; 404. Dichroic mirror 2; 405. Long-pass filter; 406. Focusing lens 1; 407. Near-infrared camera; 408. Focusing lens 2; 409. Visible light camera; 410. Host computer; 501. White LED light source; 502. Light homogenizing and beam expanding device; 503. Mirror 8; 504. Illumination objective lens. Detailed implementation manners

[0055] In order to make the objectives and advantages of the present invention clearer, the present invention will be specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific implementation manners of the present invention, and does not strictly limit the scope of protection specifically claimed by the present invention.

[0056] As Figures 1-4 shown, a non-linear optical tweezer based on the spectral change of a temporal lens includes a temporal lens module, a pulse compression module, a collimation and beam expansion module, a sampling imaging module, and an illumination module, wherein the core of the sampling imaging module is a non-linear optical tweezer based on the spectral change of a temporal lens.

[0057] Among them, the time lens module includes a continuous light source 101, a polarization controller 102, a phase modulator 103, a radio frequency signal generator 104, a preamplifier 105, a polarization controller 106, an intensity modulator 107, a power amplifier 108, and an optical fiber port 109; the pulse compression module includes a spatial light collimator 201, a quarter-wave plate 202, a half-wave plate 203, a mirror 204, a spatial grating 205, a spatial grating 206, a mirror 207, a mirror 208, a mirror 209, and a mirror 210; the collimation and beam expansion module includes a mirror 301, a galvanometer scanner 302, a beam expansion lens 303, and a beam expansion lens 304; the sampling imaging module includes a mirror 401, a dichroic mirror 402, a capture objective lens 403, a dichroic mirror 404, a long-pass filter 405, a focusing lens 406, a near-infrared camera 407, a focusing lens 408, a visible light camera 409, and a host computer 410; the illumination module includes a white light LED light source 501, a light homogenizer and beam expander 502, a mirror 503, and an illumination objective lens 504;

[0058] The main solution is as follows: The continuous light output by the continuous laser as the continuous light source 101 enters the phase modulator 103 after polarization control. The phase modulator 103 receives the sine signal emitted by the radio frequency signal generator 104 and performs secondary phase modulation to expand the continuous light spectrum. Subsequently, it enters the preamplifier 105 for optical power amplification to prepare for subsequent pulse compression. The amplified light then enters the intensity modulator 107. The intensity modulator 107 receives the radio frequency signal emitted by the synchronized radio frequency signal generator 104 for pulse cutting, and then the power amplifier 108 adjusts the power and outputs it through the optical fiber port 109. The pulsed light after pulse cutting is collimated by the spatial light collimator 201 and output as a collimated beam into space. A pair of spatial gratings, as the dispersion medium, realizes the pulse width compression of the pulsed light and the spatial output of the ultrashort pulsed light. Subsequently, the ultrashort pulsed light is fiber-expanded after passing through the galvanometer scanner 302 and the beam expansion lens group, and enters the capture objective lens 403 through the dichroic mirror by the mirror to achieve particle capture. After particle capture is completed, the image is transmitted back by the capture objective lens 403. After being split by the dichroic mirror, one beam of light enters the near-infrared camera 407 to determine the particle capture position; the other beam of light enters the visible light camera 409 for capture imaging. Finally, both images are collected by the host computer 410 for capture image acquisition and capture force analysis. The system illuminates the sample with white light from the white light LED through the light homogenizer and the illumination objective lens 504 to facilitate particle capture imaging.

[0059] In this solution, after the continuous light source 101 outputs continuous light to the first polarization controller 102, the first polarization controller 102 performs polarization control to conform to the polarization state required for subsequent second-phase modulation. After the polarization state adjustment is completed, the continuous light is input to the phase modulator 103. The phase modulator 103 receives the sine signal wave emitted by the radio frequency signal generator 104 to perform second-phase modulation on the continuous light. The phase-modulated continuous laser is converted into a linear chirped pulse with a 10 GHz repetition frequency, and its spectrum is correspondingly broadened. Subsequently, the broadened light is power-amplified by the preamplifier 105. After amplification, the intensity modulator 107 receives the radio frequency signal synchronized by the radio frequency signal generator 104 to perform pulse cutting. By adjusting the repetition frequency of the radio frequency signal, the spectrum of the pulsed light can be adjusted. The pulsed light signal after cutting is then power-amplified and adjusted by the power amplifier 108, and output through the fiber optic port 109; the pulsed light after cutting in the time lens module still has a relatively large pulse width and needs to be further compressed by the pulse compression module. The laser beam output from the fiber optic port 109 is spatially collimated by the spatial light collimator 201 and then output. Subsequently, the quarter-wave plate 202 and the half-wave plate 203 are used to select the grating polarization state adaptation. After the polarization state adaptation, the light beam is reflected by the first mirror 204 and enters the spatial dispersion compression region composed of the first spatial grating 205 and the second spatial grating 206. Then, it enters the compression region again through the second mirror 207 to achieve secondary compression of the pulse width. Subsequently, it is reflected by the third mirror 208, the fourth mirror 209, and the fifth mirror 210 to achieve the output of the ultrashort compressed pulsed light; the pulsed light compressed by the pulse compression module is reflected by the sixth mirror 301 and enters the collimation and beam expansion module. The galvanometer 302 controls the scanning of the light beam through the sampling imaging module. Subsequently, the beam expander composed of the first beam expansion lens 303 and the second beam expansion lens 304 expands the light beam; the ultrashort pulsed light after beam expansion is reflected by the seventh mirror 401 and transmitted to the first dichroic mirror 402. Subsequently, it is transmitted and enters the capture objective lens 403 to capture particles. The captured image is transmitted back by the capture objective lens 403. After being reflected by the first dichroic mirror 402, it is transmitted to the second dichroic mirror 404 and divided into two beams with different wavelength ranges. Among them, the beam image in the near-infrared range is transmitted through the long-pass filter 405 and then focused by the first focusing lens 406 onto the near-infrared camera 407 to determine the capture point. On the other hand, the beam in the visible light range is reflected to the second focusing lens 408 and then focused onto the visible light camera 409 for capture imaging. The beam images of these two parts are both transmitted to the host computer 410 for acquisition and processing; the illumination module illuminates the captured image of the optical tweezer system. The white light source emitted by the white light LED light source 501 is processed by the light homogenizing and beam expanding device 502 and then reflected by the eighth mirror 503 to the illumination objective lens 504 for focusing illumination;

[0060] In the solution, the continuous light source 101 is controlled by an internal temperature control system to keep the inside of the laser cavity stable and output continuous laser with a narrow linewidth. The continuous light source 101 has the functions of adjustable external voltage power and adjustable external current wavelength. The functions of polarization controller 1 102 and polarization controller 2 106 are to control the polarization state of the optical fiber beam. The function of the phase modulator 103 is to receive the external input carrier frequency signal and use the internal phase modulation crystal to achieve linear chirped pulse output and spectral broadening. The function of the radio frequency signal generator 104 is to modulate the output and delay adjustment of the radio frequency signal and the cutting radio frequency signal. The function of the preamplifier 105 is to amplify the optical power of the continuous optical signal. The function of the intensity modulator 107 is to receive the external input radio frequency signal and achieve pulse cutting through the transfer function. The function of the power amplifier 108 is to adjust the power of the pulse-cut optical signal. The function of the optical fiber port 109 is to output the pulse-cut optical signal through the optical fiber.

[0061] In the solution, the function of the spatial light collimator 201 is to collimate the non-parallel light beam output from the port into a parallel light beam, ensure the effective transmission of light energy and reduce the divergence of the light beam. The function of the quarter-wave plate 202 is to perform phase modulation on the polarization state of the incident light, so that the polarization direction of the light changes. The function of the half-wave plate 203 is to rotate the polarization direction of the incident light by a certain angle by introducing a phase difference to match the polarization direction of the pulse compression grating pair. The functions of mirror 1 204, mirror 2 207, mirror 3 208, mirror 4 209, mirror 5 210, mirror 6 301, mirror 7 401, and mirror 8 503 are to reflect the incident light beam and change the propagation direction of the light beam. The functions of spatial grating 1 205 and spatial grating 2 206 are to act as dispersion media to compress the pulse width of the pulsed light.

[0062] In the solution, the functions of dichroic mirror 1 402 and dichroic mirror 2 404 are to selectively reflect or transmit light of different wavelengths. Specifically, they reflect light in a specific wavelength range and allow light of other wavelengths to pass through. The function of the capture objective lens 403 is to focus the laser beam and use the light pressure of the light beam to act on the micro-particles, so as to achieve the capture and manipulation of the particles and at the same time realize the imaging of particle capture. The function of the long-pass filter 405 is to only allow light with a wavelength greater than the set cut-off wavelength to pass through and block shorter wavelength light at the same time. The functions of focusing lens 1 406 and focusing lens 2 408 are to focus the incident light beam onto the camera imaging area to achieve imaging. The function of the near-infrared camera 407 is to image the transmitted near-infrared light image to confirm the position of the capture point. The function of the visible light camera 409 is to transmit the image captured in the visible light range. The function of the host computer 410 is to control the galvanometer 302 and collect and analyze the captured images.

[0063] In the solution, the function of the white light LED light source 501 is to provide uniform white light illumination by emitting light including multiple wavelengths, usually red, green, and blue light; the function of the light homogenizing and beam expanding device 502 is to homogenize and expand the light beam emitted by the illuminating white light LED light source 501, making the light field flatter and more uniform, and avoiding the problems of overly concentrated light spots or uneven brightness; the function of the illumination objective lens 504 is to focus the light beam emitted by the light source onto the sample or target area to achieve uniform illumination, helping to obtain high-quality images or perform precise measurements;

[0064] The present invention provides a non-linear optical tweezer based on the spectral change of a temporal lens, which performs spectral broadening by using a temporal lens module for quadratic phase modulation and pulse cutting; uses a pulse compression optical path, introduces dispersion by a spatial grating pair, and realizes pulse width compression of pulsed light through dispersion compensation; uses a collimation and beam expansion module to expand the light beam of the ultrashort pulsed light to match the entrance pupil of the capture objective lens 403 to achieve the maximum capture efficiency; in the non-linear optical tweezer based on the spectral change of the temporal lens, the optical Kerr effect is introduced by using ultrashort pulsed light, and the spectral change of the pulsed light is realized by adjusting the cutting repetition frequency, improving the capture force of the particles and extending the manipulation range in time, and being able to observe and manipulate the target for a longer time under low-damage operation.

[0065] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. The structures, devices, and operation methods not specifically described and explained in the present invention are implemented according to the conventional means in the art without special description and limitation.

Claims

1. A nonlinear optical tweezers based on the spectrum change of time lens, characterized in that: It includes a time lens module, a pulse compression module, a collimation and beam expansion module, a sampling and imaging module, and an illumination module; The time lens module is used to output continuous light that has undergone polarization control and secondary phase modulation in sequence, convert the continuous light into a linear chirped pulse light signal and perform power amplification, and then perform pulse cutting and power amplification on the linear chirped pulse light signal before output; The pulse compression module is used to compress the linear chirped pulse light signal output by the time lens module and output an ultrashort compressed pulse light; The collimation and beam expansion module is used to reflect the ultrashort compressed pulse light compressed by the pulse compression module into a light beam, and then perform beam scanning and beam expansion to form an ultrashort pulse light; The sampling imaging module is used to capture particles of ultrashort pulse light, and divide the captured image into a near-infrared range light beam and a visible light range light beam for image capture; The lighting module is used to illuminate the captured image.

2. The nonlinear optical tweezers based on time lens spectrum variation according to claim 1, characterized in that: The time lens module comprises a continuous light source (101), a polarization controller 1 (102), a phase modulator (103), a radio frequency signal generator (104), a preamplifier (105), a polarization controller 2 (106), an intensity modulator (107), a power amplifier (108), and an optical fiber port (109); The continuous light source (101) is used to output continuous light to a polarization controller (102); The polarization controller 1 (102) is used to perform polarization control on the continuous light, and input the continuous light after polarization state adjustment into the phase modulator (103); The radio frequency signal generator (104) is used to emit a radio frequency signal; The phase modulator (103) receives the sinusoidal signal wave emitted by the radio frequency signal generator (104) to perform secondary phase modulation on the continuous light, and the continuous laser light after the phase modulation is converted into a linear chirped pulse; The preamplifier (105) is used to amplify the power of the linear chirped pulse optical signal; The intensity modulator (107) is used to perform pulse cutting by receiving a synchronized radio frequency signal from a radio frequency signal generator (104) after the power of the linear chirped pulse optical signal is amplified; The power amplifier (108) is used to perform power amplification and adjustment on the cut linear chirped pulse optical signal; The optical fiber port (109) is used to output the linear chirped pulse optical signal amplified by the power amplifier (108).

3. The nonlinear optical tweezers based on time lens spectrum variation according to claim 2, characterized in that: The pulse compression module comprises a spatial light collimator (201), a quarter wave plate (202), a half wave plate (203), a reflector 1 (204), a spatial grating 1 (205), a spatial grating 2 (206), a reflector 2 (207), a reflector 3 (208), a reflector 4 (209), and a reflector 5 (210); The spatial light collimator (201) is used to perform spatial light collimation on the laser beam output from the optical fiber port (109); The quarter wave plate (202) is used to phase modulate the polarization state of the incident light so that the polarization direction of the light changes; The half-wave plate (203) rotates the polarization direction of the incident light to adapt to the polarization direction of the pulse compression grating pair by introducing a phase difference; The spatial grating 1 (205) and the spatial grating 2 (206) are used as dispersion media to realize pulse width compression of pulse light, forming a spatial dispersion compression region; The reflector 1 (204) is used to reflect the light beam after polarization state adaptation into the spatial dispersion compression region; The second reflector (207) is used to reflect the reflected light beam into the compression area for a second time, thereby achieving a second compression of the pulse width; The reflector three (208), the reflector four (209) and the reflector five (210) are used to reflect the secondary compressed light beam to achieve the output of ultra-short compressed pulse light.

4. The nonlinear optical tweezers based on time lens spectrum variation according to claim 3, characterized in that: The collimating and beam expanding module comprises a reflector six (301), a galvanometer (302), a beam expanding lens one (303), and a beam expanding lens two (304); Reflector six (301) is used to reflect the ultra-short compressed pulse light compressed by the pulse compression module into the collimation and beam expansion module; The galvanometer (302) realizes the scanning of the light beam through the control of the sampling imaging module; The first beam expander lens (303) and the second beam expander lens (304) form a beam expander, and the beam expander is used to expand an ultrashort pulse beam.

5. The nonlinear optical tweezers based on time lens spectrum variation according to claim 4, characterized in that: The sampling imaging module includes a reflector seven (401), a dichroic mirror one (402), a capture lens (403), a dichroic mirror two (404), a long-pass filter (405), a focusing lens one (406), a near-infrared camera (407), a focusing lens two (408), a visible light camera (409), and a host computer (410); The reflector seven (401) is used to reflect the expanded ultrashort pulse light beam to the dichroic mirror one (402) and transmit the light beam through the dichroic mirror one (402) into the capture objective lens (403); The capture lens (403) is used to capture particles and transmit the captured image back to the dichroic mirror 1 (402); The second dichroic mirror (404) is used to separate the captured image into a beam image in a near-infrared range and a beam image in a visible light range; The long-pass filter (405) is used to block light shorter than a set cut-off wavelength in a near-infrared range light beam image; The focusing lens 1 (406) is used to focus the image of the light beam in the near-infrared range transmitted through the long-pass filter (405) onto the near-infrared camera (407) to determine the capture point; The second focusing lens (408) is used to focus the light beam in the visible light range onto the visible light camera (409); The visible light camera (409) is used to capture and image a light beam in the visible light range; The host computer (410) is used to collect and process the light beam image in the near-infrared range and the light beam image in the visible light range.

6. The nonlinear optical tweezers based on the time lens spectrum variation according to claim 5, characterized in that: The lighting module comprises a white light LED light source (501), a light homogenizing beam expander (502), a reflector eight (503), and a lighting objective lens (504); The white light LED light source (501) is used to emit white light; The light homogenizing beam expander (502) is used to homogenize and expand the white light; The reflector eight (503) is used to reflect the white light processed by the light homogenizing beam expander (502) to the illumination objective lens (504); The illumination objective lens (504) is used to focus white light onto a sample or a target area to achieve uniform illumination for focused illumination.

7. The nonlinear optical tweezers based on the time lens spectrum variation according to claim 6, characterized in that: The white light emitted by the white light LED light source (501) includes red light, green light and blue light.

8. The nonlinear optical tweezers based on time lens spectrum variation according to claim 1, characterized in that: The frequency of the linear chirped pulse optical signal is 10 GHz.

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