A laser control device capable of time dispersion compensation and an ophthalmic surgery apparatus

Abstract

This invention belongs to the field of laser modulation technology and discloses a laser control device and ophthalmic surgical equipment capable of achieving temporal dispersion compensation. The laser control device includes a beam splitter, a temporal dispersion compensation component, and a spatial dispersion component. When first polarized light is incident on the beam splitter, it is output in a first direction and then transmitted to the temporal dispersion compensation component. The temporal dispersion compensation component changes the polarization direction of the first polarized light, causing temporal dispersion in the beam and outputting second polarized light. The second polarized light is output in a second direction via the beam splitter and then transmitted to the spatial dispersion component. The spatial dispersion component outputs a target parallel beam with spatial dispersion, and the temporal dispersion caused by the spatial dispersion component is compensated by the temporal dispersion compensation component. This invention can achieve spatiotemporal focusing and compensate for the temporal dispersion caused by spatiotemporal focusing, reducing the laser focal pulse width, ensuring focal energy, and improving cutting efficiency and accuracy.

Description

Technical Field

[0001] This invention belongs to the field of laser modulation technology, and more specifically, relates to a laser control device and ophthalmic surgical equipment that can achieve time dispersion compensation. Background Technology

[0002] Femtosecond pulsed lasers have extremely short pulse durations and extremely high peak energies, enabling them to achieve high-precision, low-heat processing. In recent years, with the development of high-power, special-wavelength femtosecond lasers, femtosecond laser technology has been applied in many fields.

[0003] Spatiotemporal focusing, as a novel focusing method, spatially separates the laser beam frequency to generate spatial chirp, and then spatially reassembles it at the objective lens focal plane to achieve out-of-focus defocusing. This results in a change in pulse width along the propagation direction after focusing, with the minimum pulse width at the focal point. When cutting tissue, the absorbed energy for tissue ablation is inversely proportional to the pulse width; a smaller pulse width results in higher peak energy, thus achieving better cutting performance at the focal point. Outside the focal point, the pulse width increases, and the absorbed energy decreases sharply. Simultaneously, spatiotemporal focusing widens the laser spot in one direction, thereby increasing the lateral spot size and improving cutting throughput. Therefore, spatiotemporal focusing technology enables rapid and precise cutting.

[0004] Chinese patent CN107335923A uses parallel, oppositely placed gratings to achieve spatiotemporal focusing of femtosecond lasers for machining metal surfaces, proposing that spatiotemporal focusing technology can effectively suppress nonlinear effects in material processing. However, due to the inherent negative temporal dispersion introduced by the dual-grating optical path structure, the peak pulse width at the focal point of the focused spot decreases sharply, affecting the cutting quality. For example, if the laser output pulse width is 500 fs, theoretically, after spatiotemporal focusing, the pulse width at the objective lens focal point should be 500 fs. However, due to temporal dispersion, the pulse width at the focal point can increase to 1 ps, thus attenuating the cutting energy by half and affecting the cutting efficiency. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides a laser control device and ophthalmic surgical equipment that can realize time dispersion compensation, the purpose of which is to compensate for the time dispersion of the beam caused by spatiotemporal focusing.

[0006] To achieve the above objectives, according to one aspect of the present invention, a laser control device capable of temporal dispersion compensation is provided, comprising a beam splitter, a temporal dispersion compensation component, and a spatial dispersion component; when first polarized light is incident on the beam splitter, the first polarized light is output in a first direction via the beam splitter and subsequently transmitted to the temporal dispersion compensation component, the temporal dispersion compensation component is used to change the polarization direction of the first polarized light and cause temporal dispersion in the beam, outputting second polarized light, the temporal dispersion being the different propagation times of different wavelengths of light in the temporal dispersion compensation component; the second polarized light is output in a second direction via the beam splitter and subsequently transmitted to the spatial dispersion component, the second direction being different from the first direction; the spatial dispersion component includes a third grating and a fourth grating arranged in parallel, the beam incident on the spatial dispersion component undergoes grating diffraction sequentially through the third grating and the fourth grating, outputting a target parallel beam with spatial chirp, and the temporal dispersion caused by the spatial dispersion component is compensated by the temporal dispersion compensation component;

[0007] The time dispersion compensation component includes a first waveplate, a first lens, a second lens, a first grating, a second grating, and a first reflector. The first lens and the second lens share the same optical axis. After the first polarized light is incident on the time dispersion compensation component, its beam passes through the first grating, the first lens, the second lens, and the second grating in sequence, and then outputs a parallel beam that is perpendicularly incident on the first reflector. After being reflected by the first reflector, the beam returns through the original optical path and is output from the time dispersion compensation component. The first waveplate is placed in the optical path of the time dispersion compensation component. After the first polarized light passes through the first waveplate twice, its polarization direction is adjusted to obtain the second polarized light.

[0008] Optionally, the first grating is located on the side of the first lens away from the second lens, and the incident light area of ​​the first grating is located at the focal point of the first lens. The first grating is parallel to the optical axis of the lens and faces the diffraction center of the first lens. The focal lengths of the first lens and the second lens are both f and they are 2f apart. The second grating is located on the side of the second lens away from the first lens. The projection of the incident light area of ​​the second grating onto the optical axis of the lens does not exceed the focal point of the second lens. During the propagation of light from the first grating to the second grating, its exit angle at the first grating is equal to its incident angle at the second grating.

[0009] Optionally, the laser control device further includes a displacement stage, on which the second grating and the first reflector remain fixed in relative position. The displacement stage can move along the optical axis of the second lens to change the distance between the second lens and the second grating.

[0010] Optionally, one of the first polarized light and the second polarized light is horizontally linearly polarized light, and the other is vertically linearly polarized light; the first waveplate is a quarter-wave plate; one of the first polarized light and the second polarized light is transmitted through the beam splitter, and the other is reflected by the beam splitter.

[0011] Optionally, the first waveplate is placed between the beam splitter and the first grating.

[0012] Optionally, the laser control device further includes a beam expander and a second waveplate; the beam expander is used to receive the laser generated by the laser source and expand it, and the expanded laser is transmitted to the second waveplate through an optical path and then its polarization direction is adjusted by the second waveplate to obtain the first polarized light.

[0013] Optionally, the laser control device further includes a second reflection component, which is disposed between the beam splitter and the spatial dispersion component, for directing the beam output by the beam splitter in the second direction to the third grating in the spatial dispersion component at a set angle.

[0014] Optionally, the laser control device further includes a controller, a three-dimensional scanning component, and an objective lens. The three-dimensional scanning component is controlled by the controller. The three-dimensional scanning component is used to receive the target parallel light output by the fourth grating and change the direction of the target parallel light under the control of the controller. The parallel light output by the three-dimensional scanning component is focused by the objective lens to the position to be cut to achieve three-dimensional scanning cutting.

[0015] Optionally, the laser control device further includes an imaging component for imaging the cutting process of the surface to be processed.

[0016] According to another aspect of the present invention, an ophthalmic surgical device is provided, which includes a laser control device as described above, wherein a controller in the laser control device is used to determine a target cutting trajectory on the surface of the patient's eyeball according to surgical parameters and to control a three-dimensional scanning component to change the direction of the target parallel light to achieve three-dimensional scanning cutting of the surface of the eyeball according to the target cutting trajectory.

[0017] In summary, compared with the prior art, the technical solutions conceived in this invention have the following main advantages:

[0018] 1. In this invention, a spatial dispersion component is used to control the spatial dispersion of the light beam, thereby controlling the shape of the output light spot. However, spatial dispersion of the light beam leads to temporal dispersion, meaning that different wavelengths of light experience different path lengths from their initial incidence on the third grating, through diffraction by the third and fourth gratings, to reach the same position. Therefore, different wavelengths of light take different propagation times to reach the same position, meaning they cannot reach the same position simultaneously, resulting in a decrease in focused energy and affecting processing efficiency. To solve this problem, this invention, in addition to the spatial dispersion component, also adds a beam splitter and a temporal dispersion compensation component. The beam splitter is used to adjust the output light of the temporal dispersion compensation component to match the original input light spot. The light from the dispersion compensation component undergoes optical path separation to effectively acquire the light output from the temporal dispersion compensation component and transmit it to the spatial dispersion compensation component. The temporal dispersion compensation component comprises a first waveplate, a first lens, a second lens, a first grating, a second grating, and a first reflector. The arrangement of the first lens, second lens, first grating, second grating, and first reflector must ensure that the light beam, after propagating through the temporal dispersion compensation component, can return along its original path. Thus, temporal dispersion can be introduced into the light beam through a simple optical path configuration. Furthermore, by setting the first waveplate to change the polarization direction of the light, it is separated from the original incident light after passing through the beam splitter. Since the light beam exhibits temporal dispersion after passing through the temporal dispersion compensation component, it can compensate for the temporal dispersion in the spatial dispersion component. Therefore, this invention, combining a beam splitter, a temporal dispersion compensation component, and a spatial dispersion component, can achieve both spatiotemporal focusing and compensate for the temporal dispersion caused by spatiotemporal focusing, thereby improving the laser cutting energy and ensuring cutting efficiency.

[0019] 2. In this invention, the above-mentioned laser control device is applied to ophthalmic surgery. Firstly, the spatial dispersion component achieves spatiotemporal focusing, which generates spatial chirp, thereby increasing the lateral size and widening the focused spot. Widening the scanning spot improves cutting efficiency. Secondly, the pulse width of the spatiotemporal focusing changes axially, with the pulse width being smallest and the energy highest only at the focal point. Therefore, higher cutting precision is achieved using the laser at the focal point. Thirdly, the temporal dispersion compensation component pre-compensates for the temporal dispersion introduced by spatiotemporal focusing, reducing the pulse width at the focal point and maintaining the light energy at the focal point for better cutting. Therefore, using the ophthalmic surgical device proposed in this invention can greatly improve surgical efficiency, increase surgical precision, and ensure surgical safety. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a laser control device according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the laser control device in another embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the laser control device including the imaging component of the present invention;

[0023] Figure 4 The diagram shows the difference in focused beams after traditional Gaussian focusing and spatiotemporal focusing. In (a), the three focused beams are the cross-sections of the 8mm Gaussian beam, the 4mm Gaussian beam, and the spatiotemporal focused beam that is expanded from the 4mm beam to the 8mm beam on the focal plane xoy, respectively. In (b), the three focused beams are the cross-sections of the 8mm Gaussian beam, the 4mm Gaussian beam, and the spatiotemporal focused beam that is expanded from the 4mm beam to the 8mm beam on the focal plane yoz, respectively.

[0024] Figure 5 This is a graph showing the change in fluorescence intensity with compensation position in one embodiment;

[0025] Figure 6 This is a fluorescence brightness diagram of different compensation positions in one embodiment, where (a) to (e) correspond to different compensation positions respectively;

[0026] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0027] 1. First grating; 2. First lens; 3. Second lens; 4. Second grating; 5. First mirror; 6. Laser source; 7. Beam expander assembly; 8. Second mirror; 9. Second waveplate; 10. Beam splitter; 11. Third mirror; 12. Fourth mirror; 13. Third grating; 14. Fourth grating; 15. 3D scanning assembly; 16. Objective lens; 17. Surface to be processed; 18. Controller; 19. First waveplate; 20. Camera; 21. Dichroic mirror. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0029] This invention provides a laser control device capable of achieving time-dispersion compensation, such as... Figure 1 The diagram shown is a schematic diagram of a laser control device in one embodiment of the present invention, which includes a beam splitter 10, a temporal dispersion compensation component, and a spatial dispersion component.

[0030] When the first polarized light is incident on the beam splitter 10, the first polarized light is output in the first direction through the beam splitter 10 and then transmitted to the time dispersion compensation component. The time dispersion compensation component is used to change the polarization direction of the first polarized light and cause time dispersion in the beam, outputting the second polarized light. Time dispersion means that the propagation time of different wavelengths of light in the time dispersion compensation component is different. The second polarized light is output in the second direction through the beam splitter 10 and then transmitted to the spatial dispersion component. The second direction is different from the first direction. The spatial dispersion component includes a third grating 13 and a fourth grating 14 arranged in parallel. The beam incident on the spatial dispersion component undergoes grating diffraction through the third grating 13 and the fourth grating 14 in sequence and outputs a target parallel beam.

[0031] In the spatial dispersion assembly, the third grating 13 and the fourth grating 14 are placed parallel to each other and opposite to each other. By adjusting the incident angle of the light rays of the third grating 13 and the fourth grating 14 and the distance between the two gratings, the spatial dispersion broadening of the laser beam can be adjusted, spatial chirp can be generated, and a parallel beam with spatial broadening can be output.

[0032] The time dispersion compensation component includes a first waveplate 19, a first lens 2, a first lens 3, a first grating 1, a second grating 4, and a first reflector 5. The first lens 2 and the first lens 3 share the same optical axis. The light beam incident on the time dispersion compensation component passes through the first grating 1, the first lens 2, the second lens 3, and the second grating 4 in sequence, and then outputs a parallel light beam that is perpendicularly incident on the first reflector 5. After being reflected by the first reflector 5, the light beam returns through the original optical path and is output from the time dispersion compensation component. The first waveplate 19 is placed in the optical path of the time dispersion compensation component. After the first polarized light passes through the first waveplate 19 twice, its polarization direction is adjusted to obtain the second polarized light.

[0033] In this invention, a spatial dispersion component is used to achieve spatial dispersion control of the light beam, thereby controlling the shape of the output light spot. Furthermore, in addition to the spatial dispersion component, a beam splitter and a temporal dispersion compensation component are added. The beam splitter separates the light output from the temporal dispersion compensation component from the original input light, effectively acquiring the light output from the temporal dispersion compensation component and transmitting it to the spatial dispersion compensation component. The temporal dispersion compensation component includes a first waveplate, a first lens, a second lens, a first grating, a second grating, and a first reflector. The arrangement of the first lens, second lens, first grating, second grating, and first reflector must ensure that the light beam can return along its original path after propagating through the temporal dispersion compensation component. Thus, negative temporal dispersion can be achieved through simple optical path configuration. Furthermore, by setting the first waveplate to change the polarization direction of the light, it is separated from the original incident light after passing through the beam splitter. The negative temporal dispersion of the light beam after passing through the temporal dispersion compensation component can precisely compensate for the positive temporal dispersion in the spatial dispersion component. Therefore, this invention combines a beam splitter, a temporal dispersion compensation component, and a spatial dispersion component to achieve both spatiotemporal focusing and compensation for temporal dispersion caused by spatiotemporal focusing, thereby maintaining the laser focal pulse width, ensuring focal energy, and improving cutting efficiency and accuracy.

[0034] In one embodiment, to ensure the common optical path of light in the time dispersion compensation component, the first lens 2, the first lens 3, the first grating 1, the second grating 4, and the first reflector 5 can be designed as follows:

[0035] The first grating 1 is located on the side of the first lens 2 away from the second lens 3, and the incident light area of ​​the first grating 1 is located at the focal point of the first lens 2. The first grating 1 is parallel to the optical axis of the lens and faces the diffraction center of the first lens 2. The focal lengths of the first lens 2 and the second lens 3 are both f and they are 2f apart. The second grating 4 is located on the side of the second lens 3 away from the first lens 2. The projection of the incident light area of ​​the second grating 4 onto the optical axis of the lens does not exceed the focal point of the second lens 3. During the propagation of light from the first grating 1 to the second grating 2 along the optical path, its exit angle at the first grating 1 is equal to its incident angle at the second grating 4.

[0036] In this embodiment, the first grating and the second grating are placed symmetrically and opposite to each other. A 4f system consisting of two identical lenses is added between the two gratings. Theoretically, the beam emitted from the second lens 3 is completely symmetrical to the beam incident on the first lens 2. The polarized beam from the beam splitter 10 enters the first grating 1 at a certain angle. The first grating 1 is placed at the front focal point of the 4-f system. The diffraction center beam enters the 4-f system perpendicularly. The time dispersion compensation of the beam is different depending on the position of the second grating 4 or the incident angle of the incident light received from the second lens 3. The angle of the first reflecting mirror 5 ensures that the reflected light returns along the original path. The beam changes its polarization angle after passing through the 1 / 4 wave plate twice, and enters the subsequent optical path after passing through the beam splitter 10.

[0037] In one embodiment, the laser control device further includes a displacement stage, on which the second grating 4 and the first reflector 5 remain fixed in relative position. The displacement stage can move along the optical axis of the second lens 3 to change the distance between the second lens 3 and the second grating 4.

[0038] In this embodiment, the distance between the second lens 3 and the second grating 4 is changed by moving the displacement stage. Different distances result in different amounts of time dispersion compensation for the light beam, thereby achieving adjustable time dispersion compensation.

[0039] In one embodiment, one of the first polarized light and the second polarized light is horizontally linearly polarized light, and the other is vertically linearly polarized light. The first waveplate is a quarter-wave plate, which can rotate the polarization state of the laser beam by 45°. One of the first polarized light and the second polarized light is transmitted through the beam splitter 10, and the other is reflected by the beam splitter 10.

[0040] For example, such as Figure 1 As shown, assuming the first polarized light is horizontally linearly polarized light and the second polarized light is vertically linearly polarized light, the horizontally linearly polarized light is transmitted from the beam splitter 10 and enters the time dispersion compensation component. After passing through the quarter-wave plate twice in the time dispersion compensation component, the vertically linearly polarized light is output. After being reflected by the beam splitter 10, the vertically linearly polarized light is transmitted to the spatial dispersion component through the optical path.

[0041] In one embodiment, the first waveplate 19 is placed between the beam splitter 10 and the first grating 1. For example, after the incident light passes through the beam splitter 10, the first waveplate 19, the first grating 1, the first lens 2, the second lens 3, and the second grating 4, it returns via the first reflecting mirror 5 at the end and exits from the other side of the beam splitter 10 through the same optical path. Then it enters the spatial dispersion section, and after passing through, a spatially chirped beam with pre-compensated temporal dispersion is obtained. It can be understood that the first waveplate 19 can also be placed at other positions in the optical path of the temporal dispersion compensation component, as long as it is ensured that the first polarized light can pass through the first waveplate 19 twice to obtain the second polarized light.

[0042] In one embodiment, such as Figure 2 As shown, the laser control device also includes a beam expander 7 and a second waveplate 9. The beam expander 7 is used to receive the laser beam generated by the laser source and expand it. The expanded laser beam is transmitted to the second waveplate 9 through the optical path, and then the polarization direction is adjusted by the second waveplate 9 to obtain the first polarized light. Specifically, the second waveplate 9 can be a half-wave plate.

[0043] In one embodiment, the laser control device further includes a laser source 6, which generates a laser beam and transmits it to the beam expander 7. Specifically, the laser source 6 can be a femtosecond laser source. Specifically, the operating wavelength of the laser source 6 can cover the ultraviolet band, visible light band, infrared band, etc.

[0044] In one embodiment, the laser control device further includes a first reflection component disposed between the beam expander 7 and the second waveplate 9, for transmitting the beam output from the beam expander 7 to the second waveplate 9. For example, the first reflection component includes a second reflector 8, through which the beam output from the beam expander 7 is reflected to the second waveplate 9.

[0045] In one embodiment, the laser control device further includes a second reflection component disposed between the beam splitter 10 and the spatial dispersion component, for directing the beam output from the beam splitter 10 in the second direction to the third grating 13 in the spatial dispersion component at a set angle. For example, the second reflection component includes a third mirror 11 and a fourth mirror 12, and the second polarized light output from the beam splitter 10 is reflected sequentially by the third mirror 11 and the fourth mirror 12 before being transmitted to the spatial dispersion component.

[0046] In one embodiment, the laser control device further includes a controller 18, a three-dimensional scanning component 15, and an objective lens 16. The three-dimensional scanning component 15 is controlled by the controller 18 and is used to receive the target parallel light output from the fourth grating 14 and change the direction of the target parallel light under the control of the controller 18. The objective lens 16 is used to focus the parallel light output from the three-dimensional scanning component 15 onto the surface 17 to be processed to achieve three-dimensional scanning processing. Specifically, the three-dimensional scanning component 15 includes an axial scanning component and a transverse scanning component.

[0047] In one embodiment, the laser control device further includes an imaging component for imaging the cutting process. For example, such as Figure 3 As shown, the imaging assembly includes a dichroic mirror 21 and a camera 20. The dichroic mirror 21 is placed between the objective lens 16 and the three-dimensional scanning assembly 15. The processing light from the surface to be processed is reflected by the dichroic mirror 21 to the camera 20 for imaging.

[0048] like Figure 4The diagram shows the difference in focused beams between traditional Gaussian focusing and spatiotemporal focusing. In (a), the three focused beams are the cross-sections of an 8mm Gaussian beam, a 4mm Gaussian beam, and a spatiotemporally focused beam expanded from a 4mm beam to an 8mm beam on the focal plane xoy, respectively. In (b), the three focused beams are the cross-sections of an 8mm Gaussian beam, a 4mm Gaussian beam, and a spatiotemporally focused beam expanded from a 4mm beam to an 8mm beam on the focal plane yoz, respectively. It can be seen that spatiotemporal focusing can increase the lateral dimension while keeping the axial dimension basically unchanged. Moreover, the axial pulse width varies along the propagation direction, with the pulse width being the smallest only at the focal point. Therefore, it can better compress the axial dimension.

[0049] The temporal dispersion compensation effect of the present invention will be verified below.

[0050] Because the fluorescence intensity of a fluorescent indicator is related to the pulse width of a femtosecond pulse, the fluorescence intensity and pulse width are inversely proportional. The fluorescence intensity reaches its maximum when the pulse width τ is at its minimum. Therefore, to verify the compensation effect, a fluorescent material, such as rhodamine, is placed as an indicator after the objective lens is focused, and the pulse width change is verified. By adjusting the distance between the second lens 3 and the second grating 4, the compensation amount of the time dispersion compensation component is adjusted. By observing the fluorescence intensity of the fluorescent material in the system, the relationship between the compensation effect and the compensation amount can be intuitively determined. At a certain compensation position, the fluorescence intensity of the fluorescent indicator is observed to be at its maximum, which can be considered as the femtosecond pulse light pulse width being at its minimum and the dispersion compensation effect being optimal, thus determining the optimal compensation position. After compensation is completed, the grating position can be fixed for subsequent material processing.

[0051] like Figure 5 The figure shows a curve illustrating the change in fluorescence intensity with compensation position in one embodiment. The graph shows that the fluorescence intensity of the rhodamine indicator reaches its maximum at a distance of 60.2 mm, indicating that this position provides the best compensation effect and the smallest pulse width. Figure 6 The figure shows fluorescence intensity diagrams at different compensation positions in one embodiment, where (a) to (e) correspond to different compensation positions respectively. The fluorescence bright spot in Figure (c) is the strongest, indicating that its compensation position is optimal.

[0052] Accordingly, the present invention also provides an ophthalmic surgical device, which includes the laser control device described above. The controller in the laser control device is used to determine the target cutting trajectory on the surface of the patient's eyeball according to surgical parameters and to control the three-dimensional scanning component to change the direction of the target parallel light to achieve three-dimensional scanning and cutting of the eyeball surface according to the target cutting trajectory. Specifically, ophthalmic surgeries include, but are not limited to, refractive surgery and cataract surgery.

[0053] In ophthalmic surgery, tissue ablation is achieved through laser point-by-point scanning. The smaller the laser spot, the smaller the required point spacing, the more scanning points per unit area, and the longer the time required. For example, scanning an 8mm diameter surface requires approximately three times the scanning time of a 1μm focused spot compared to a 3μm spot. Faster scanning speeds can reduce the incidence of negative pressure desorption, improving surgical safety. Ensuring scanning quality leads to better postoperative results. Therefore, improving scanning speed while maintaining scanning quality is a crucial issue that femtosecond laser ophthalmic surgery needs to address. The ophthalmic surgical device provided by this invention, firstly, utilizes a spatial dispersive component to achieve spatiotemporal focusing, generating spatial chirp, thereby increasing the lateral size and widening the focused spot. Widening the scanning spot improves ablation efficiency. Secondly, the pulse width of the spatiotemporal focusing laser changes axially, with the pulse width being smallest and the energy highest only at the focal point. Therefore, higher ablation precision is achieved using the laser at the focal point. Third, the temporal dispersion compensation component can pre-compensate for the temporal dispersion introduced by spatiotemporal focusing, reducing the pulse width at the focal point and thus maintaining the light energy at the focal point for better ablation. Therefore, using the ophthalmic surgical device proposed in this invention can greatly improve surgical efficiency, enhance surgical precision, and ensure surgical safety.

[0054] Furthermore, the controller also regulates the laser source output and adjusts the dispersion compensation amount.

[0055] Specifically, the axial scanning of the three-dimensional scanning component can be achieved by a Galilean or Keplerian magnification structure, while the lateral scanning part can be composed of a galvanometer, a resonant mirror, an acousto-optic deflector, a liquid crystal spatial light modulator, and a digital microlens array.

[0056] In one embodiment, the operation process of the ophthalmic surgical device is as follows:

[0057] The femtosecond laser emits a polarized laser beam. After beam expansion and collimation, the laser beam passes through a beam splitter and a quarter-wave plate for the first time along the first optical path. Then, the polarized beam enters the first grating at a certain angle. After time dispersion compensation, the reflected beam passes through the quarter-wave plate and beam splitter for the second time and enters the second optical path. Subsequently, the beam enters the spatial dispersion section at a certain angle in the second optical path and becomes collimated light with spatial chirp. Then, it enters the objective lens through the three-dimensional scanning section, and the objective lens focuses the light for surgical processing until the processing is completed.

[0058] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "again" are intended to illustrate the present invention and are not intended to limit the present invention.

[0059] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A laser control device capable of achieving time-dispersion compensation, characterized in that, The system includes a beam splitter, a temporal dispersion compensation component, and a spatial dispersion component. When first polarized light is incident on the beam splitter, the first polarized light is output in a first direction via the beam splitter and then transmitted to the temporal dispersion compensation component. The temporal dispersion compensation component is used to change the polarization direction of the first polarized light and cause temporal dispersion in the beam, outputting second polarized light. The temporal dispersion refers to the different propagation times of light of different wavelengths in the temporal dispersion compensation component. The second polarized light is output in a second direction via the beam splitter and then transmitted to the spatial dispersion component. The second direction is different from the first direction. The spatial dispersion component includes a third grating and a fourth grating arranged in parallel. The beam incident on the spatial dispersion component undergoes grating diffraction sequentially through the third grating and the fourth grating, outputting a target parallel beam with spatial chirp. The temporal dispersion caused by the spatial dispersion component is compensated by the temporal dispersion compensation component. The time dispersion compensation component includes a first waveplate, a first lens, a second lens, a first grating, a second grating, and a first reflector. The first lens and the second lens share a common optical axis. After the first polarized light is incident on the time dispersion compensation component, its beam passes through the first grating, the first lens, the second lens, and the second grating in sequence, and then outputs a parallel beam that is perpendicularly incident on the first reflector. After being reflected by the first reflector, the beam returns through the original optical path and is output from the time dispersion compensation component. The first waveplate is placed in the optical path of the time dispersion compensation component. After the first polarized light passes through the first waveplate twice, its polarization direction is adjusted to obtain the second polarized light. The first grating is located on the side of the first lens away from the second lens, and the incident light area of ​​the first grating is located at the focal point of the first lens. The first grating is parallel to the optical axis of the lens and faces the diffraction center of the first lens. The focal lengths of the first lens and the second lens are both f and they are 2f apart. The second grating is located on the side of the second lens away from the first lens. The projection of the incident light area of ​​the second grating onto the optical axis of the lens does not exceed the focal point of the second lens. During the propagation of light from the first grating to the second grating, its exit angle at the first grating is equal to its incident angle at the second grating. The laser control device further includes a displacement stage, on which the second grating and the first reflector remain fixed in relative position. The displacement stage can move along the optical axis of the second lens to change the distance between the second lens and the second grating.

2. The laser control device as described in claim 1, characterized in that, One of the first polarized light and the second polarized light is horizontally linearly polarized light, and the other is vertically linearly polarized light. The first waveplate is a quarter-wave plate. One of the first polarized light and the second polarized light is transmitted through the beam splitter, and the other is reflected by the beam splitter.

3. The laser control device as described in claim 1, characterized in that, The first waveplate is placed between the beam splitter and the first grating.

4. The laser control device as described in claim 1, characterized in that, The laser control device further includes a beam expander and a second waveplate. The beam expander is used to receive the laser generated by the laser source and expand it. The expanded laser is transmitted to the second waveplate through an optical path and then its polarization direction is adjusted by the second waveplate to obtain the first polarized light.

5. The laser control device as described in claim 1, characterized in that, The laser control device further includes a second reflection component, which is disposed between the beam splitter and the spatial dispersion component, and is used to direct the beam output by the beam splitter in the second direction to the third grating in the spatial dispersion component at a set angle.

6. The laser control device according to any one of claims 1 to 5, characterized in that, The laser control device further includes a controller, a three-dimensional scanning component, and an objective lens. The three-dimensional scanning component is controlled by the controller. The three-dimensional scanning component is used to receive the target parallel light output by the fourth grating and change the direction of the target parallel light under the control of the controller. The parallel light output by the three-dimensional scanning component is focused by the objective lens to the position to be cut to achieve three-dimensional scanning cutting.

7. The laser control device as described in claim 6, characterized in that, The laser control device also includes an imaging component for imaging the cutting process of the surface to be processed.

8. An ophthalmic surgical device, characterized in that, The device includes the laser control device as described in claim 6 or 7, wherein the controller in the laser control device is used to determine the target cutting trajectory on the surface of the patient's eyeball according to surgical parameters, and to control the three-dimensional scanning component to change the direction of the target parallel light to achieve three-dimensional scanning cutting of the surface of the eyeball according to the target cutting trajectory.

Images