Optical system and method for laser annealing an optical waveguide based on the optical system

Abstract

The application provides an optical system and a method for optical annealing of an optical waveguide based on the optical system, and the optical system comprises a laser, a transmission system, a focusing lens, a translation stage, an observation system and a camera; the laser is used for emitting laser; the laser is transmitted to the camera through one light path of the transmission system, and the camera is used for monitoring the beam profile and size of the laser; the laser is transmitted to the focusing lens through another light path of the transmission system, and the focusing lens is used for focusing the laser to an optical element on a chip surface to be processed, so as to perform laser annealing on the optical waveguide of the optical element; and the observation system is used for observing the position of a laser spot irradiated to the chip surface to be processed. The selective annealing treatment of only the optical waveguide of the optical element on the chip surface is realized by using the laser, the whole process is non-contact, the energy is precisely controllable, the thermal influence area is strictly limited, the surface roughness of the optical waveguide can be reduced without damaging the peripheral integrated devices, and the waveguide loss is reduced from the physical root.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to an optical system and a method for laser annealing of optical waveguides based on the optical system. Background Technology

[0002] Currently, in the field of integrated photonic chips, scattering loss caused by the surface roughness of optical waveguides is a key bottleneck limiting performance improvement. Traditional global thermal annealing methods are limited in application due to the risk of damage to other sensitive components integrated on the chip at high temperatures. Therefore, there is an urgent need for a post-processing technique that can achieve localized, low-temperature, and efficient processing. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an optical system and a method for laser annealing of optical waveguides based on the optical system, so as to achieve laser annealing and selectively process optical waveguides by means of highly controllable laser energy, thereby providing an innovative solution for accurately reducing the surface roughness of optical waveguides and thus reducing losses without affecting surrounding devices.

[0004] In a first aspect, embodiments of the present invention provide an optical system for laser annealing. The optical system includes: a laser, a transmission system, a focusing lens, a translation stage, an observation system, and a camera. A chip to be processed is placed on the translation stage. The laser is used to emit laser light. The laser light is transmitted to the camera through one optical path of the transmission system, and the camera is used to monitor the beam shape and size of the laser light. The laser light is transmitted to the focusing lens through another optical path of the transmission system, and the focusing lens is used to focus the laser light onto an optical element on the surface of the chip to be processed, so as to perform laser annealing on the optical waveguide of the optical element. The observation system is used to observe the position of the laser spot on the surface of the chip to be processed.

[0005] In an optional embodiment of this application, the optical system further includes: a control system connected to the laser and also connected to the translation stage; the control system is used to control the switching on and power of the laser; the control system is also used to control the motion path and speed of the translation stage.

[0006] In an optional embodiment of this application, the transmission system includes: a beam expander, a reflector, and a beam splitter; the beam expander is used to enlarge the spot diameter and collimate the laser emitted by the laser; the reflector is used to guide the beam propagation direction of the laser after passing through the beam expander; the beam splitter is used to split the laser after passing through the reflector into two beams, one of which is transmitted to the camera and the other to the focusing lens.

[0007] In an optional embodiment of this application, the above-mentioned beam expanding system includes two convex lenses, the distance between the two convex lenses being equal to the sum of the focal lengths of the two convex lenses.

[0008] In an optional embodiment of this application, the translation stage includes a linear slide and a rotary slide; the translation stage is used to move in multiple directions via the linear slide and the rotary slide so that the laser spot irradiates the area to be processed on the chip to be processed; wherein, the area to be processed on the chip to be processed is provided with optical elements.

[0009] In an optional embodiment of this application, the observation system described above includes an HDMI camera, which includes a CCD camera.

[0010] In an optional embodiment of this application, the control system includes: a computer and a motion control card; the computer is used to acquire control parameters of the laser or translation stage and generate control commands based on the control parameters; the motion control card is used to generate drive signals based on the control commands and send the drive signals to the laser or translation stage.

[0011] Secondly, embodiments of the present invention also provide a method for laser annealing of optical waveguides based on an optical system. Applied to the aforementioned optical system, a chip to be processed is placed on a translation stage. The method includes: a laser emitting a laser beam; the laser beam being transmitted to a camera via one optical path of a transmission system, the camera monitoring the beam shape and size of the laser beam; the laser beam being transmitted to a focusing lens via another optical path of the transmission system, the focusing lens focusing the laser beam onto an optical element on the surface of the chip to be processed, thereby performing laser annealing on the optical waveguide of the optical element; and an observation system observing the position of the laser spot irradiated onto the surface of the chip to be processed.

[0012] In optional embodiments of this application, the above method further includes: the control system controlling the switching on and power of the laser; and the control system controlling the motion path and speed of the translation stage.

[0013] In optional embodiments of this application, the above method further includes: a beam expander system enlarges the spot diameter and collimates the laser emitted by the laser; a reflector guides the beam propagation direction of the laser after passing through the beam expander system; and a beam splitter splits the laser after passing through the reflector into two beams, one of which is transmitted to the camera and the other to the focusing lens.

[0014] The embodiments of the present invention bring the following beneficial effects: This invention provides an optical system and a method for laser annealing of optical waveguides based on the optical system. The optical system is used for laser annealing, and a chip to be processed is placed on a translation stage. A laser emits a laser beam; the laser beam is transmitted to a camera through one optical path of a transmission system, and the camera monitors the beam shape and size of the laser beam; the laser beam is transmitted to a focusing lens through another optical path of the transmission system, and the focusing lens focuses the laser beam onto the optical element on the surface of the chip to be processed, so as to perform laser annealing on the optical waveguide of the optical element; an observation system observes the position of the laser spot on the surface of the chip to be processed. In this method, selective annealing of only the waveguide itself can be achieved by laser. The entire process is non-contact, the energy is precisely controllable, and the heat-affected zone is strictly limited. Therefore, waveguide loss can be reduced from the physical source without damaging surrounding integrated devices.

[0015] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0016] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of an optical system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of an optical system that uses a laser to perform optical annealing on an optical waveguide, as provided in an embodiment of the present invention. Figure 3 This is an effect diagram of a method for optical annealing of silicon optical waveguides based on an optical system, provided in an embodiment of the present invention. Figure 4 This is a flowchart of a method for laser annealing of an optical waveguide based on an optical system, provided as an embodiment of the present invention.

[0019] Icons: 1-Laser; 2-Beam expander system; 3-Reflector; 4-Beam splitter; 5-Focusing lens; 6-Translation stage; 7-Observation system; 8-Control system; 9-Camera; 10-Transmission system. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Currently, in the field of integrated photonic chips, scattering loss caused by the surface roughness of optical waveguides is a key bottleneck limiting performance improvement. Traditional global thermal annealing methods are limited in application due to the risk of damage to other sensitive components integrated on the chip at high temperatures. Therefore, there is an urgent need for a post-processing technique that can achieve localized, low-temperature, and efficient processing.

[0022] Based on this, the present invention provides an optical system and a method for laser annealing of optical waveguides based on the optical system. Specifically, it provides a method for achieving localized, low-temperature, and efficient laser optical annealing of chips, which can reduce optical waveguide losses. In this embodiment, a laser with a wavelength that can be absorbed by the waveguide material is used. After being focused by the optical system, the laser spot is precisely aligned and irradiated onto the optical waveguide to be processed. By controlling the laser power and scanning speed, the laser spot moves relative to the waveguide path for scanning. The laser energy is locally absorbed by the waveguide and converted into heat energy, generating instantaneous high temperature, thereby achieving selective annealing of only the waveguide itself.

[0023] The core working principle of the optical system in this embodiment is "laser-induced selective local thermal effect": when a focused laser irradiates the waveguide, the light energy is effectively absorbed by the waveguide material (such as silicon, silicon nitride, or lithium niobate), generating instantaneous high temperatures within a very small effective volume (typically comparable to the waveguide size). This high-temperature effect promotes improvements in two aspects of the microstructure: (1) Atom migration and recombination: Atoms on the waveguide sidewalls and near-surface rough protrusions gain sufficient kinetic energy to migrate to the depressions, thereby achieving surface smoothing and reducing light scattering.

[0024] (2) Defect repair: Lattice defects and amorphous regions introduced by etching and other processes inside the material are repaired under thermal action, reducing the number of scattering centers in the body.

[0025] The entire process is non-contact, with precise and controllable energy, and the thermally affected area is strictly limited. Therefore, waveguide loss can be reduced from the physical source without damaging surrounding integrated devices.

[0026] To facilitate understanding of this embodiment, an optical system disclosed in this embodiment of the invention will first be described in detail.

[0027] Example 1: This invention provides an optical system, see [link to relevant documentation]. Figure 1 The diagram shows a schematic of an optical system used for laser annealing. The system includes a laser 1, a transmission system 10, a focusing lens 5, a translation stage 6, an observation system 7, and a camera 9. A chip to be processed is placed on the translation stage 6. The laser 1 emits a laser beam. The laser beam is transmitted through one optical path of the transmission system 10 to the camera 9, which monitors the beam shape and size. The laser beam is also transmitted through another optical path of the transmission system 10 to the focusing lens 5, which focuses the laser beam onto an optical element on the surface of the chip to be processed, thus performing laser annealing on the optical waveguide of the optical element. The observation system 7 observes the position of the laser spot on the surface of the chip to be processed.

[0028] In this embodiment, the laser can be a femtosecond laser; the translation stage can be a high-precision six-dimensional translation stage, which carries the chip to be processed and drives the sample stage or focusing lens to move with high precision and controllability. like Figure 1 As shown, the optical system also includes: a control system 8, which is connected to the laser 1 and also connected to the translation stage 6; the control system 8 is used to control the switching on and power of the laser 1; the control system 8 is also used to control the movement path and speed of the translation stage 6.

[0029] The control system in this embodiment can control the switching on and power of the laser, as well as the movement path and speed of the translation stage. The control system can control the translation stage to ensure that the laser only illuminates the area to be processed on the chip, thus performing laser annealing on the optical waveguide of the optical element.

[0030] The control system includes a computer and a motion control card. The computer is used to acquire control parameters of the laser or translation stage and generate control commands based on the control parameters. The motion control card is used to generate drive signals based on the control commands and send the drive signals to the laser or translation stage.

[0031] In this embodiment, the computer can acquire control parameters of the laser or translation stage input by the user and generate control commands based on these parameters. The motion control card can generate drive signals based on the control commands and send these drive signals to the laser or translation stage. The laser can control its switching on and power based on the drive signals, or the translation stage can control its motion path and speed based on the drive signals.

[0032] In some embodiments, the observation system described above includes an HDMI (High Definition Multimedia Interface) camera, which includes a CCD camera.

[0033] The observation system in this embodiment can be a stand-alone, multi-dimensional, high-performance observation system, including an 8-megapixel HDMI camera, 0.7-4.5X optical magnification, a maximum electronic magnification of 240x, and 1:7 zoom. This stand-alone, multi-dimensional, high-performance observation system can observe the position of the laser spot, ensuring that the laser spot accurately illuminates the area to be processed on the chip.

[0034] In this embodiment, the camera can be a CCD (Charge-Coupled Device) camera, used to observe the shape and size of the laser beam.

[0035] This invention provides an optical system in which a chip to be processed is placed on a translation stage; a laser emits a laser beam; the laser beam is transmitted to a camera through one optical path of a transmission system, and the camera monitors the beam shape and size of the laser beam; the laser beam is transmitted to a focusing lens through another optical path of the transmission system, and the focusing lens focuses the laser beam onto an optical element on the surface of the chip to be processed; an observation system observes the position of the laser spot on the surface of the chip to be processed. In this method, selective annealing of the waveguide itself can be achieved using a laser. The entire process is non-contact, the energy is precisely controllable, and the heat-affected zone is strictly limited. Therefore, waveguide loss can be reduced from the physical source without damaging surrounding integrated devices.

[0036] Example 2: This invention provides another optical system, implemented based on the foregoing embodiments, with a focus on describing the specific structure of the transmission system. For example... Figure 1 As shown, the transmission system includes: a beam expander 2, a reflector 3, and a beam splitter 4; the beam expander 2 is used to enlarge the spot diameter and collimate the laser emitted by the laser 1; the reflector 3 is used to guide the propagation direction of the laser beam after passing through the beam expander 2; the beam splitter 4 is used to split the laser beam after passing through the reflector 3 into two beams, one of which is transmitted to the camera 9, and the other is transmitted to the focusing lens 5.

[0037] In this embodiment, the laser can be a femtosecond laser, which can be a fiber laser. The emitted femtosecond laser passes sequentially through a beam expander, a reflector, a beam splitter, a focusing lens, and a translation stage.

[0038] like Figure 1 As shown, the beam expander system 2 in this embodiment includes two convex lenses, the distance between which is equal to the sum of the focal lengths of the two convex lenses.

[0039] The beam expander system in this embodiment can enlarge the diameter of the laser spot and collimate the beam. The reflector can guide the direction of beam propagation. The beam splitter can split the laser beam into two beams, one of which enters the focusing lens and the other enters the CCD camera. The focusing lens can focus the femtosecond laser onto the surface of the chip sample.

[0040] In some embodiments, the translation stage includes a linear slide and a rotary slide; the translation stage is used to move in multiple directions via the linear slide and the rotary slide to illuminate the processing area on the chip to be processed; wherein the processing area on the chip to be processed is provided with optical elements.

[0041] The high-precision six-dimensional translation stage in this embodiment can be precisely adjusted in six directions, including a three-axis linear slide and a three-axis high-precision rotary slide. The translation accuracy is at the nanometer level. It carries the chip to be processed and enables the femtosecond laser spot to accurately scan the area to be processed on the chip through precise movement.

[0042] Example 3: This invention provides another optical system, implemented based on the foregoing embodiments. The focus is on describing the specific method by which the optical system utilizes laser to perform optical annealing on the optical waveguide. See also... Figure 2 The diagram shows an optical system that uses a laser to perform optical annealing on an optical waveguide.

[0043] The optical system in this embodiment can utilize laser optical annealing to reduce the optical waveguide loss of silicon material. The optical system can be configured as follows: a femtosecond laser is a fiber laser with an output laser center wavelength of 655 nm, a pulse width less than 600 fs, an average power greater than 10 W, and a repetition frequency less than 1 MHz; a beam expander system corresponding to a center wavelength of 655 nm is used to amplify the laser spot diameter; a reflector corresponding to a center wavelength of 655 nm is used to reflect the laser beam to the focusing lens; a beam splitter corresponding to a 655 nm laser has a beam splitting ratio of 1:9, emitting 10% of the light to the CCD camera and projecting 90% of the light to the focusing lens; the reflector corresponding to a center wavelength of 655 nm has a focal length of 2.4 mm when using laser optical annealing to reduce silicon material, and 5 mm when using laser optical annealing to reduce lithium niobate material. The reflector focuses the incident laser spot size to below 1 micrometer; the six-dimensional translation stage uses a high-performance slide with a sensitivity of 50 nm to support optical chip samples prepared from silicon or lithium niobate materials. The chip can be made of materials with a linewidth of 400 nm. The system is constructed from a silicon-based optical waveguide with a wavelength of nm. The camera is an 8-megapixel HDMI camera with functions such as measurement, photography, video recording, and plotting. It is equipped with a high-definition 4K display. The control system has laser control software and translation stage control software, which can simultaneously control laser parameters and translation stage movement speed and path.

[0044] See Figure 3 The image shows the effect of a method for optical annealing of silicon optical waveguides based on an optical system. Figure 3 The annealing effect on silicon waveguides is shown. Figure 3(a) shows the surface roughness data of the silicon optical waveguide before laser annealing, measured by atomic force microscopy. Figure 3 (b) shows the surface roughness data of the silicon waveguide after laser annealing, measured by atomic force microscopy. The experimental data show that the arithmetic mean roughness (Ra) of the waveguide decreased from 1.45 nm to 0.408 nm and the root mean square roughness (RMS) decreased from 2.22 nm to 0.547 nm after laser annealing.

[0045] Example 4: This invention provides a method for laser annealing of optical waveguides based on an optical system, implemented on the basis of the aforementioned embodiments. It is applied to the optical system provided in the aforementioned embodiments, with a chip to be processed placed on a translation stage. (See also...) Figure 4 The flowchart shown illustrates a method for laser annealing of an optical waveguide based on an optical system. This method includes the following steps: Step S402: The laser emits a laser beam.

[0046] In this embodiment, the laser can be a femtosecond laser. The power supply of the femtosecond laser is turned on, and the various parameters of the laser are adjusted. The femtosecond laser wavelength is set to 655 nm, the pulse width is 600 fs, the average power is 10 W, and the repetition frequency is 1 MHz.

[0047] In step S404, the laser beam is transmitted to the camera through one optical path of the transmission system, and the camera monitors the shape and size of the laser beam.

[0048] In some embodiments, the beam expander system enlarges the spot diameter and collimates the laser emitted by the laser; the reflector guides the beam propagation direction of the laser after passing through the beam expander system; the beam splitter splits the laser after passing through the reflector into two beams, one of which is transmitted to the camera and the other to the focusing lens.

[0049] In this embodiment, the femtosecond laser emitted by the femtosecond laser is expanded to a beam diameter of 2 mm through a beam expansion system, while ensuring parallel beam transmission.

[0050] In this embodiment, the collimated laser beam can be passed through a reflector into a beam splitter, so that the incident direction of the beam spot is at 45° with the beam splitter. 10% enters the CCD camera and 90% enters the focusing lens. The size and shape of the beam spot are observed through the CCD camera. By adjusting the beam expansion system and the angle of the beam splitter, the beam spot is made to be circular with a diameter of 2 mm.

[0051] In step S406, the laser is transmitted to the focusing lens through another optical path of the transmission system. The focusing lens focuses the laser onto the optical element on the surface of the chip to be processed, so as to perform laser annealing on the optical waveguide of the optical element. The observation system observes the position of the laser spot on the surface of the chip to be processed.

[0052] In this embodiment, the projected laser beam can be focused into a 1µm spot using a focusing lens.

[0053] In some embodiments, the control system controls the switching on and power of the laser; the control system controls the movement path and speed of the translation stage.

[0054] In this embodiment, the translation stage can be controlled by the control system to position the surface of the chip to be processed at the focal point of the lens; the horizontal position of the translation stage can be adjusted by the control system, and the light spot can be observed by the observation system to ensure that the light spot illuminates the area to be processed on the chip; in this embodiment, the translation stage can be moved by the control system to make the light spot sweep evenly across the entire optical waveguide.

[0055] The method provided in this embodiment of the invention can reduce the loss of silicon optical waveguides by using laser optical annealing. The results of the embodiments show that, compared with silicon optical waveguides before and after laser annealing, the waveguide sidewalls are smoother and the loss is lower after laser annealing, and it does not affect the function of other devices on the chip.

[0056] This invention provides a method for laser annealing of optical waveguides using an optical system. A chip to be processed is placed on a translation stage; a laser emits a laser beam; the laser beam is transmitted through one optical path of a transmission system to a camera, which monitors the beam shape and size; the laser beam is transmitted through another optical path of the transmission system to a focusing lens, which focuses the laser beam onto an optical element on the surface of the chip to be processed; an observation system observes the position of the laser spot on the surface of the chip. This method allows for selective annealing of only the waveguide itself using laser technology. The entire process is non-contact, with precisely controllable energy and a strictly limited heat-affected zone, thus reducing waveguide loss from its physical source without damaging surrounding integrated devices.

[0057] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the laser annealing method for optical waveguides based on optical systems described above can be referred to the corresponding process in the foregoing embodiments, and will not be repeated here.

[0058] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0059] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0060] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An optical system, characterized in that, The optical system is used for laser annealing, and includes: a laser, a transmission system, a focusing lens, a translation stage, an observation system, and a camera; the chip to be processed is placed on the translation stage; The laser is used to emit laser light; The laser beam is transmitted to the camera through one optical path of the transmission system, and the camera is used to monitor the beam shape and size of the laser beam. The laser is transmitted to the focusing lens through another optical path of the transmission system. The focusing lens is used to focus the laser onto the optical element on the surface of the chip to be processed, so as to perform laser annealing on the optical waveguide of the optical element. The observation system is used to observe the position of the laser spot on the surface of the chip to be processed.

2. The optical system according to claim 1, characterized in that, The optical system further includes a control system, which is connected to the laser and also connected to the translation stage; The control system is used to control the switching on and power of the laser; The control system is also used to control the motion path and speed of the translation stage.

3. The optical system according to claim 1, characterized in that, The transmission system includes: a beam expander, a reflector, and a beam splitter; The beam expanding system is used to enlarge the spot diameter and collimate the laser beam emitted by the laser. The reflector is used to guide the propagation direction of the laser beam after passing through the beam expander system; The beam splitter is used to split the laser beam after it passes through the reflector into two beams. One beam is transmitted to the camera, and the other beam is transmitted to the focusing lens.

4. The optical system according to claim 3, characterized in that, The beam expander system includes two convex lenses, the distance between the two convex lenses being equal to the sum of their focal lengths.

5. The optical system according to claim 1, characterized in that, The translation stage includes: a linear slide and a rotary slide; The translation stage is used to move in multiple directions via the linear slide and the rotary slide to illuminate the processing area on the chip to be processed by the laser spot; wherein the processing area on the chip to be processed is provided with the optical element.

6. The optical system according to claim 1, characterized in that, The observation system includes an HDMI camera, which includes a CCD camera.

7. The optical system according to claim 2, characterized in that, The control system includes: a computer and a motion control card; The computer is used to acquire control parameters of the laser or the translation stage, and generate control commands based on the control parameters; The motion control card is used to generate drive signals based on the control commands, and send the drive signals to the laser or the translation stage.

8. A method for laser annealing of optical waveguides based on an optical system, characterized in that, Applied to the optical system according to any one of claims 1-7, wherein a chip to be processed is placed on a translation stage, the method includes: The laser emits laser light; The laser beam is transmitted to the camera through one optical path of the transmission system, and the camera monitors the beam shape and size of the laser beam. The laser is transmitted to a focusing lens through another optical path of the transmission system. The focusing lens focuses the laser onto an optical element on the surface of the chip to be processed, so as to perform laser annealing on the optical waveguide of the optical element. The observation system observes the position of the laser spot on the surface of the chip to be processed.

9. The method according to claim 8, characterized in that, The method further includes: The control system controls the switching on and power of the laser; The control system controls the movement path and speed of the translation stage.

10. The method according to claim 8, characterized in that, The method further includes: The beam expanding system enlarges the spot diameter and collimates the laser beam emitted by the laser. The reflector guides the propagation direction of the laser beam after passing through the beam expander system; The beam splitter divides the laser beam after it passes through the reflector into two beams. One beam is transmitted to the camera, and the other beam is transmitted to the focusing lens.

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