Method and device for processing chalcogenide photon chip based on laser-induced atomic exchange

Abstract

The invention discloses a chalcogenide photon chip processing method and device based on laser-induced atom exchange. The method comprises the following steps: preparing a sulfide film on the surface of a medium substrate; placing the dielectric substrate prepared with the sulfide film in a closed laser direct writing processing space; processing parameters of the laser direct writing processing space are controlled, laser-induced atom exchange is carried out on the sulfide film, the chalcogenide photon chip is obtained, the processing parameters comprise laser spot scanning parameters and atmosphere environment parameters, and the atmosphere environment parameters comprise that the oxygen content of mixed gas is within a preset range. Activation energy needed by reaction is controlled by adjusting the oxygen content of the mixed gas within the preset range and controlling the concentration of reactants, when the oxygen content is reduced, the activation energy needed by the reaction is increased, so that the reaction threshold value is increased, the reaction can be carried out only at the part, with higher energy, of the focused laser beam, and the reaction efficiency is improved. Therefore, machining breaking through the optical diffraction limit is achieved.

Description

Technical Field

[0001] This invention relates to the field of photonic chip fabrication technology, and more specifically, to a method and apparatus for fabricating chalcogenide photonic chips based on laser-induced atomic exchange. Background Technology

[0002] With the continuous progress and development of information science and technology and modern industry, people have fully entered the information age, placing great emphasis on the demand for key technologies such as information acquisition, processing, storage, and transmission. In recent years, the competition between electronics and photonics, two exciting technologies, has intensified to achieve ubiquitous functionality ranging from imaging and communication to sensing and medicine. While electronics has made remarkable progress in data processing and storage, as well as logical operations, photonic platforms are better suited for information transmission, primarily due to their higher speed and greater bandwidth. However, to catch up with electronics' advantages in integrability and reprogrammability, photonics needs to develop into next-generation reconfigurable miniaturized systems with tunable properties to fully manipulate the information carriers within photonic platforms. Nanophotonics has gained widespread attention due to its unique ability to shape light fields in the subwavelength range. Metasurfaces (MSs) and photonic integrated circuits (PICs) enable the large-scale production of cost-effective planar optical elements for imaging, sensing, and communication. To enable multi-purpose applications in nanophotonics, chalcogenide phase change materials (PCMs) have been introduced as a promising platform for tunable and reconfigurable nanophotonics frameworks. The integration of non-volatile chalcogenide PCMs offers unique properties such as strong optical contrast, fast switching speeds, and long-term stability, providing substantial programmable reconfiguration capabilities for traditional static nanophotonics platforms.

[0003] Currently, most nanophotonic platforms (metasurfaces and integrated photonic devices) are fabricated using complementary metal-oxide-semiconductor (COMS) processes. However, each of these methods for fabricating photonic devices has its own advantages and disadvantages. For example, dry etching waveguides have good surface smoothness, but require expensive lithography machines and etching equipment, and the process is relatively complex. The lift-off method is a low-temperature process, and thin film deposition after patterning makes this process more advantageous in fabricating residue-free waveguides and avoiding developer corrosion of chalcogenide waveguides. However, it requires expensive equipment and complex processes. Nanoimprinting is suitable for chalcogenide thin film materials with low glass transition temperatures, and has the advantages of low cost, short preparation cycle, and large-scale production. However, this technology has certain limitations, such as film decomposition and crystallization during the imprinting process, difficulty in separating the mold from the device during demolding, and easy damage to the sidewalls, thereby increasing the transmission loss of the waveguide. Laser direct writing eliminates the need for expensive high-precision masks, improves preparation efficiency, and reduces costs. However, it requires the chalcogenide material to be photosensitive. The refractive index of chalcogenide thin films may change again under high-power laser light, or even cause permanent thermal damage, leading to changes in transmission mode or increased transmission loss. Therefore, developing a low-cost, high-efficiency chalcogenide photonic platform processing technology with a large refractive index modulation depth is of great significance.

[0004] Laser direct writing technology fully utilizes the easily oxidized properties of chalcogenide materials to achieve efficient processing of chalcogenide integrated photonic chips. This innovative method abandons the complex etching process of traditional silicon-based processes, directly inducing the oxidation reaction of chalcogenide materials through laser direct writing, thereby achieving patterned processing, significantly improving processing efficiency and reducing costs. However, the minimum feature size and processing resolution of devices fabricated by laser direct writing technology are limited by the diffraction limit of light. Existing laser direct writing technology cannot break through the theoretical limit of laser processing. While far-field wavefront modulation and near-field focusing techniques are difficult to implement and offer limited improvement in resolution, they are also very costly. Only by significantly overcoming the optical diffraction limit can large-scale development of integrated photonic chips be further achieved. Summary of the Invention

[0005] This invention provides a method and apparatus for processing chalcogenide photonic chips based on laser-induced atomic exchange, solving the technical problem that existing laser direct writing technology cannot break through the theoretical limit of laser processing.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: The first aspect of this invention provides a method for fabricating chalcogenide photonic chips based on laser-induced atomic exchange, comprising the following steps: Sulfide films are prepared on the surface of a dielectric substrate; The dielectric substrate on which the sulfide film is prepared is placed in a closed laser direct writing processing space; By controlling the processing parameters of the laser direct writing processing space, laser-induced atomic exchange is performed on the sulfide film to obtain a chalcogenide photonic chip. The processing parameters include laser spot scanning parameters and atmospheric environment parameters. The atmospheric environment parameters include controlling the oxygen content of the mixed gas within a preset range.

[0007] Furthermore, before preparing the sulfide film on the surface of the dielectric substrate, the method further includes cleaning the dielectric substrate, including: Select a substrate that meets the design dimensions, clean the surface to remove dust particles, organic impurities, and inorganic impurities. The surface cleaning steps are as follows: The substrate was placed in a vertical cleaning basket and ultrasonically cleaned in acetone solution, isopropanol solution, and ultrapure water for 10 minutes each. Both sides were then dried with a high-purity argon gas gun and placed in a forced-air drying oven at 110°C for 5 minutes.

[0008] Furthermore, the dielectric substrate is made of a dielectric material with an absorption coefficient of less than 0.05 in the target wavelength band, which is any one of the visible light band, short-wave infrared band, mid-wave infrared band, and long-wave infrared band.

[0009] Furthermore, the sulfide film is prepared using a dielectric material with an absorption coefficient of less than 0.08 in the target wavelength band.

[0010] Furthermore, sulfide films are prepared on the surface of a dielectric substrate, including preparing sulfide films on the surface of the dielectric substrate using thermal evaporation, magnetron sputtering, atomic layer deposition, or chemical vapor deposition.

[0011] Furthermore, the thickness of the sulfide film is 100nm-300nm.

[0012] Furthermore, controlling the processing parameters of the laser direct writing processing space to perform laser-induced atomic exchange on the sulfide film includes: The atmosphere composition of the laser direct writing processing system is adjusted according to the preset atmosphere environment parameters to obtain the preset atmosphere environment; A laser spot with a preset energy distribution pattern is obtained according to a preset processing pattern; Laser spot scanning parameters are generated based on the laser spot of the preset energy distribution pattern; In the preset atmosphere, laser-induced atomic exchange is performed on the sulfide film using the laser spot according to the laser spot scanning parameters.

[0013] Furthermore, controlling the atmospheric environmental parameters includes ensuring the oxygen content of the mixed gas is within a preset range, specifically controlling the oxygen content of the mixed gas to be between 15% and 30%.

[0014] A second aspect of the present invention provides a chalcogenide photonic chip fabrication apparatus based on laser-induced atomic exchange, applying the chalcogenide photonic chip fabrication method based on laser-induced atomic exchange described in the first aspect of the present invention, comprising: a laser source, a beam adjustment system, a focusing system, a displacement system, and an atmosphere control system, wherein: The laser source is used to output a laser beam; The beam adjustment system is located between the exit end of the laser source and the focusing system, and is used to adjust the laser beam into a laser spot with a preset energy distribution pattern. The focusing system is located at the exit end of the beam adjustment system and is used to focus the laser beam and image the laser spot onto the surface of the sulfide film. The displacement system is located at the outlet end of the focusing system and is used to place the dielectric substrate on which the sulfide film is prepared. The position of the dielectric substrate on which the sulfide film is prepared is controlled by an electrical signal. The atmosphere control system is used to change the atmospheric environmental parameters of the sulfide film.

[0015] Furthermore, it also includes a processing observation system, which is disposed between the beam adjustment system and the focusing system, for observing the morphology of the processing area of ​​the sulfide film.

[0016] Compared with the prior art, the beneficial effects of the technical solution of the present invention are: This invention provides a method and apparatus for fabricating chalcogenide photonic chips based on laser-induced atomic exchange, achieving a breakthrough in the optical diffraction limit and enabling super-resolution fabrication. Existing optical fabrication technologies are limited by the Abelian diffraction limit, making it difficult to achieve nanoscale fine structure fabrication. This invention creatively utilizes the unique oxidation properties of chalcogenide materials, inducing and realizing the exchange of oxygen atoms between elements in the chalcogenide film and the environment by precisely controlling the input of external energy (such as laser). The key lies in the existence of a defined energy threshold for this atomic exchange process. First, by precisely controlling the reaction environment of the sample to be processed, the reaction threshold for atomic exchange is increased. Next, by precisely controlling the processing parameters (such as laser power and exposure time) near this threshold, the atomic exchange reaction can be triggered only in a very small area at the center of the beam focus, while the peripheral area does not react because the energy is below the threshold. This "threshold effect" makes the actual processing area much smaller than the focused spot of a traditional optical system, thus successfully breaking through the optical diffraction limit and enabling super-resolution fabrication with feature sizes below 100 nanometers or even smaller, laying the foundation for the fabrication of next-generation nanophotonic devices. Attached Figure Description

[0017] Figure 1A schematic flowchart illustrating a method for fabricating chalcogenide photonic chips based on laser-induced atomic exchange, provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a chalcogenide photonic chip processing device based on laser-induced atomic exchange, provided in an embodiment of the present invention. Figure 3 The energy distribution diagram of the focused laser spot provided in the embodiment of the present invention; Figure 4 This is a threshold energy distribution diagram of laser-induced atomic exchange reaction before controlling the oxygen content in the reaction environment, provided in an embodiment of the present invention. Figure 5 This is a threshold energy distribution diagram of laser-induced atomic exchange reaction after controlling the oxygen content in the reaction environment, provided in an embodiment of the present invention. Figure 6 A schematic diagram of a microring resonator fabricated based on laser-induced atomic exchange is provided for an embodiment of the present invention; In the figure, 1 is a silicon dioxide substrate; 2 is a sulfide thin film; 3 is an oxide layer after atomic exchange; 4 is antimony sulfide; 100 is a laser source; 200 is a beam adjustment system; 300 is a beam splitter crystal; 400 is a processing observation system; 500 is a focusing system; 600 is an atmosphere control system; 700 is a displacement system; and 800 is a dielectric substrate on which the sulfide thin film is prepared. Detailed Implementation

[0018] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] The first embodiment of the present invention provides a method for fabricating chalcogenide photonic chips based on laser-induced atomic exchange, such as... Figure 1 As shown, it includes the following steps: Sulfide films are prepared on the surface of a dielectric substrate; The dielectric substrate on which the sulfide film is prepared is placed in a closed laser direct writing processing space; By controlling the processing parameters of the laser direct writing processing space, laser-induced atomic exchange is performed on the sulfide film to obtain a chalcogenide photonic chip. The processing parameters include laser spot scanning parameters and atmospheric environment parameters. The atmospheric environment parameters include controlling the oxygen content of the mixed gas within a preset range.

[0021] This embodiment increases the reaction threshold of atomic exchange by controlling the atmosphere and concentration during processing, thereby achieving super optical resolution processing and effectively improving the accuracy of feature size. The provided laser-induced atomic exchange method for chalcogenide photonic chips has a simpler process flow and realizes single-step processing and forming of photonic chips.

[0022] In a specific embodiment, during the laser processing of chalcogenide photonic devices, this embodiment fully utilizes the easily oxidized characteristics of the chalcogenide material system, combined with laser direct writing technology, to achieve efficient and high-precision processing of chalcogenide integrated photonic chips. This embodiment's method abandons the complex etching process of traditional silicon-based processes, directly inducing the oxidation reaction of chalcogenide materials through laser direct writing, thereby achieving patterned processing, significantly improving processing efficiency and reducing costs. Furthermore, by controlling the atmosphere surrounding the chalcogenide thin film, a special atmospheric environment required for the oxidation of chalcogenide materials is provided. The essence of the chalcogenide material oxidation reaction is: under the energy provided by the laser, oxygen atoms in the surrounding environment replace sulfur atoms in the chalcogenide material, achieving atomic exchange. This further alters the original composition of the chalcogenide material, thereby changing its refractive index, and realizing the fabrication of integrated photonic devices through patterned laser direct writing technology.

[0023] Specifically, the principle of laser-induced atomic exchange in sulfide thin films is as follows: Under the energy provided by the laser, oxygen atoms in the surrounding environment replace sulfur atoms in the sulfide thin film material (taking antimony sulfide Sb₂S₃ as an example), achieving atomic exchange and undergoing an oxidation reaction to produce antimony trioxide and sulfur dioxide. The chemical reaction equation is:

[0024] In the near-infrared band of 800nm ​​to 1700nm, the refractive index of Sb2O3 is significantly lower than that of Sb2S3, with a difference of approximately 0.7. Moreover, in this band, Sb2O3 has an extinction coefficient of less than 0.01, making it a good low-absorption transparent material in the near-infrared band, suitable for the fabrication of low-loss integrated photonic devices.

[0025] Optionally, by controlling the oxygen content of the reactants, the principle of laser-induced atomic exchange in sulfide films to overcome the optical diffraction limit is as follows: In a processing area with a specific oxygen content atmosphere, the sulfide film is locally heated under the irradiation of the focused laser. The heated processing area undergoes an atomic exchange reaction with oxygen ions in the processing environment and is ultimately oxidized. The activation energy required for the reaction (i.e., the concentration of the reactants) is controlled primarily by adjusting the oxygen content of the mixed gas within a preset range. (E) When the oxygen content decreases, the activation energy required for the reaction increases, thereby raising the reaction threshold. At this point, the reaction can only occur in the part of the focused laser beam with higher energy, thus achieving breakthrough processing beyond the optical diffraction limit.

[0026] Furthermore, by combining super-resolution focused laser beams, even smaller processing feature sizes can be achieved.

[0027] In a further embodiment, before preparing the sulfide film on the surface of the dielectric substrate, the method further includes cleaning the dielectric substrate, including: Select a substrate that meets the design dimensions, clean the surface to remove dust particles, organic impurities, and inorganic impurities. The surface cleaning steps are as follows: The substrate was placed in a vertical cleaning basket and ultrasonically cleaned in acetone solution, isopropanol solution, and ultrapure water for 10 minutes each. Both sides were then dried with a high-purity argon gas gun and placed in a forced-air drying oven at 110°C for 5 minutes.

[0028] In a further embodiment, the dielectric substrate is made of a dielectric material with an absorption coefficient of less than 0.05 in the target wavelength band, including but not limited to silicon oxide, silicon nitride, lithium niobate, sapphire, calcium fluoride, crystalline silicon, or amorphous silicon; the dielectric substrate is a polished wafer structure; the target wavelength band is any one of the visible light band, short-wave infrared band, mid-wave infrared band, and long-wave infrared band.

[0029] In a further embodiment, the sulfide film is prepared using a dielectric material with an absorption coefficient of less than 0.08 in the target wavelength band, including but not limited to one or more of antimony sulfide, germanium telluride, germanium antimony telluride, germanium arsenide, and germanium telluride selenium.

[0030] In a further embodiment, a sulfide film is prepared on the surface of a dielectric substrate, including preparing the sulfide film on the surface of the dielectric substrate using thermal evaporation, magnetron sputtering, atomic layer deposition, or chemical vapor deposition.

[0031] Optionally, a thermal evaporation method is used to prepare the sulfide film, specifically: Place the substrate on the sample stage of the vacuum coating machine and fix it with clamps; evacuate the vacuum coating machine to 10... -6 The phase change material target glass was heated using a tantalum evaporation boat, and a thin film was deposited at a deposition rate of 0.2-0.8 A / s. The deposition rate and film thickness were monitored in real time by a film thickness gauge inside the deposition machine. The prepared phase change material thin film was analyzed for composition using energy-dispersive X-ray spectroscopy (EDS).

[0032] Preferably, the deposition rate is 0.5 A / s.

[0033] Optionally, sulfide thin films are prepared using magnetron sputtering, specifically: The sulfide target is fixed on the cathode, and the substrate to be sputtered is placed on the anode facing the target. When the vacuum level reaches 5 x 10⁻⁶... -4 At Pa, argon gas is introduced. After the gas flow stabilizes, the ion source is turned on, the process settings file is retrieved from the monitoring program, and the cleaning process is started. After cleaning is completed, the ion source is turned off, the DC or RF power supply is adjusted to the required power, and the coating process is started until sputtering is complete.

[0034] In a further embodiment, the thickness of the sulfide film is 100nm-300nm.

[0035] In a further embodiment, controlling the processing parameters of the laser direct writing system to perform laser-induced atomic exchange on the sulfide film includes: The atmosphere composition of the laser direct writing processing system is adjusted according to the preset atmosphere environment parameters to obtain the preset atmosphere environment; A laser spot with a preset energy distribution pattern is obtained according to a preset processing pattern; Laser spot scanning parameters are generated based on the laser spot of the preset energy distribution pattern; In the preset atmosphere, laser-induced atomic exchange is performed on the sulfide film using the laser spot according to the laser spot scanning parameters.

[0036] In a further embodiment, controlling the atmospheric environmental parameters includes ensuring the oxygen content of the mixed gas is within a preset range, specifically controlling the oxygen content of the mixed gas to be between 15% and 30%.

[0037] A second embodiment of the present invention provides a chalcogenide photonic chip processing apparatus based on laser-induced atomic exchange, such as... Figure 2 As shown, the chalcogenide photonic chip fabrication method based on laser-induced atomic exchange according to the first embodiment of the present invention includes: a laser source 100, a beam adjustment system 200, a focusing system 500, a displacement system 700, and an atmosphere control system 600, wherein: The laser source 100 is used to output a laser beam, which is a continuous laser with a wavelength of 400nm-800nm ​​and a power of not less than 1W. The beam adjustment system 200 is located between the exit end of the laser source 100 and the focusing system 500, and is used to adjust the laser beam into a laser spot with a preset energy distribution pattern. By modulating the phase, amplitude, polarization, and coherence of the incident beam, a focused spot with a value less than the diffraction limit is obtained. Figure 3 As shown; The focusing system 500 is disposed at the 200 exit end of the beam adjustment system and is used to focus the laser beam and image the laser spot onto the surface of the sulfide film. The displacement system 700 is located at the outlet end of the focusing system 500 and is used to place the dielectric substrate 800 on which the sulfide film is prepared. The position of the dielectric substrate 800 on which the sulfide film is prepared is controlled by an electrical signal. The atmosphere control system 600 is used to change the atmospheric environment parameters of the sulfide film, and further control the atomic exchange reaction threshold of the laser processing process, so as to achieve super-resolution feature size that breaks through the optical diffraction limit.

[0038] Furthermore, the processing observation system 400 is disposed between the beam adjustment system 200 and the focusing system 500, and is used to observe the morphology of the processing area of ​​the sulfide film.

[0039] In a specific embodiment, a dielectric substrate on which the sulfide film is prepared is placed on a displacement system within a sealed processing space controlled by the atmosphere control system. Next, a gas environment required for processing is supplied to the sealed processing space via a gas supply system, and the gas concentration is further controlled by regulating the gas supply system through gas concentration detection. A laser source is then activated, and the laser beam sequentially passes through a beam adjustment system and a focusing system to reach the surface of the sample to be processed. The displacement system is moved via an electrical signal to achieve patterned processing. Figure 4 , 5 As shown, the reaction rate and activation energy required for the reaction are controlled by adjusting the concentration of the reacting gases through an atmosphere control system, thereby increasing the reaction threshold. Combined with a super-resolution focused laser beam, this enables the achievement of smaller processing feature sizes.

[0040] Furthermore, in the processing area of ​​the special atmosphere, the sulfide film is locally heated under the irradiation of the focused laser. The heated processing area undergoes an atomic exchange reaction with oxygen ions in the processing environment and is eventually oxidized. The processing environment includes air, oxygen, water, and one or more gases containing oxygen atoms. The special atmosphere processing environment gas supply system provides a mixed gas with a special oxygen content to the confined space.

[0041] The third embodiment of the present invention provides an integrated photonic device provided by the first embodiment of the present invention, which eliminates the need for the complex etching process of traditional silicon-based processes. It directly induces the oxidation reaction of chalcogenide materials through laser direct writing, thereby achieving patterned processing, which significantly improves processing efficiency and reduces costs.

[0042] In a further embodiment, the integrated photonic device can be applied to multiple fields such as spatial light field manipulation, on-chip optical signal transmission and processing.

[0043] In a further embodiment, the spatial light field modulation effect includes, but is not limited to, light field amplitude modulation, light field phase modulation, light field polarization modulation, reflected light field focusing, and the generation of reflected OAM vortex beams. In a further embodiment, the on-chip optical signal transmission and processing includes, but is not limited to, on-chip waveguides, on-chip Mach-Zehnder interferometers, waveguide beam splitters, microring resonators, etc. In a further embodiment, when the chalcogenide compound material has phase transition characteristics and its phase state can be controlled by external excitation signals such as light, electricity, and heat, the planar chalcogenide integrated photonic device has the characteristics of non-volatile and programmable optical response. In a further embodiment, the phase change sulfide material includes, but is not limited to, antimony sulfide, germanium tellurium sulfide, germanium antimony tellurium, germanium arsenic sulfide, germanium tellurium selenide, etc.

[0044] In a further embodiment, the dynamic control effect of the optical response includes, but is not limited to, spatial optical switches, integrated waveguide phase shifters, tunable Mach-Zehnder interferometer optical switches, micro-ring resonant optical frequency combs with tunable resonant peaks, and tunable beam splitting ratio waveguide beam splitting switches.

[0045] In a specific embodiment, a sulfide microring resonator fabricated using a chalcogenide photonic chip fabrication method based on laser-induced atomic exchange is provided, such as... Figure 6 As shown, the region pattern for laser-induced atomic exchange in the microring resonator consists of two parallel strip patterns; the width of the strip pattern is approximately 3 μm; the spacing between the two patterns is approximately 800 nm; and the diameter of the ring structure is 100 μm-500 μm.

[0046] For example, the substrate of the sulfide microring resonator sample is a silicon dioxide substrate 1; a layer of antimony sulfide 4 is deposited on the surface of the silicon dioxide substrate 1; the thickness of the antimony sulfide 4 layer is 100nm-200nm; the antimony sulfide 4 is prepared by vacuum thermal evaporation.

[0047] For example, the laser wavelength during laser processing is 532 nm; the laser spot shape is circular; and the laser spot energy distribution is Gaussian. The sample is placed on a displacement system and within a sealed processing space controlled by the atmosphere control system. A 10%-100% oxygen environment is then supplied to the sealed processing space via a gas supply system. The laser source is turned on, and the laser beam passes sequentially through a beam adjustment system and a focusing system to reach the surface of the sample to be processed. The displacement system is moved by electrical signals to achieve patterned processing of the microring resonator. The concentration of the reacting gases is controlled by the atmosphere control system to control the reaction rate and the activation energy required for the reaction, thereby increasing the reaction threshold. Combined with a super-resolution focused laser beam, a smaller processing feature size is achieved.

[0048] The advantages of the embodiments of the present invention are as follows: 1. This invention achieves a breakthrough in overcoming the optical diffraction limit, enabling super-resolution processing. Existing optical processing technologies are limited by the Abelian diffraction limit, making it difficult to achieve fine nanoscale structures. This invention creatively utilizes the unique oxidation properties of chalcogenide materials, inducing and realizing the exchange of oxygen atoms between elements in chalcogenide films and the environment by precisely controlling the input of external energy (such as laser). The key lies in the existence of a defined energy threshold for this atomic exchange process. First, the reaction environment of the sample to be processed is precisely controlled by an atmosphere control system, increasing the reaction threshold for atomic exchange. Next, by precisely controlling processing parameters (such as laser power and exposure time) near this threshold, the atomic exchange reaction can be triggered only in a very small area at the center of the beam focus, while the peripheral area does not react because the energy is below the threshold. This "threshold effect" makes the actual processing area much smaller than the focused spot of a traditional optical system, thus successfully overcoming the limitations of the optical diffraction limit and enabling super-resolution processing with feature sizes below 100 nanometers or even smaller, laying the foundation for the fabrication of next-generation nanophotonic devices.

[0049] 2. This invention achieves contactless and etching-free single-step processing, significantly improving processing efficiency and yield. Compared with traditional photonic device fabrication technologies (such as CMOS processes and nanoimprint technology), this invention has fundamental process advantages: No physical or chemical contact: CMOS processes involve complex multi-step processes such as photolithography, etching, and deposition, while nanoimprint lithography requires direct contact between the physical template and the substrate. In these processes, physical contact can lead to template damage or device structural defects, while chemical reagents used in etching steps can introduce contamination or cause sidewall roughness. This invention completely avoids physical template contact and the use of chemical etching reagents, resulting in a clean and contamination-free processing.

[0050] Single-step processing: The traditional methods described above are all multi-step processes, which are cumbersome and accumulate large errors. This invention, through an atomic exchange reaction, directly writes the required optical waveguides, gratings, and other structures in a single processing step, achieving direct conversion from thin material films to functional devices. This not only greatly simplifies the process flow, shortens processing time, and improves processing efficiency, but more importantly, it avoids alignment errors, interface defects, and material damage that may be introduced in multi-step processes. This significantly improves the structural integrity and performance consistency of the devices, ultimately leading to a substantial increase in yield.

[0051] 3. Higher refractive index modulation depth and superior device optical performance are achieved. Compared with advanced modification processing techniques such as femtosecond laser direct writing, this invention achieves a significant improvement in the quality of material modification. Femtosecond laser processing typically induces micropores, cracks, or small refractive index change regions within materials through nonlinear absorption, resulting in a relatively limited refractive index modulation depth (Δn), which restricts the performance of photonic devices (especially high-density integrated devices and strong optical field confinement devices). The atomic exchange-based processing method employed in this invention induces a more thorough phase transition and structural reorganization in chalcogenide materials, such as transformation from amorphous to crystalline states or compositional rearrangement, thereby generating a higher refractive index modulation depth within the processing region. This deeper refractive index change enables the fabricated photonic devices (such as waveguides and microring resonators) to possess lower transmission losses, higher optical field confinement capabilities, and superior optical performance, providing a reliable technical approach for realizing high-performance, miniaturized integrated photonic chips.

[0052] The same or similar labels correspond to the same or similar parts; The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for processing a chalcogenide photonic chip based on laser-induced atomic exchange, characterized in that, The method comprises the following steps: preparing a sulfide film on the surface of a medium substrate; placing the medium substrate with the prepared sulfide film into a closed laser direct writing processing space; controlling processing parameters of the laser direct writing processing space to perform laser-induced atomic exchange on the sulfide film to obtain a chalcogenide photonic chip, wherein the processing parameters include laser spot scanning parameters and atmosphere environment parameters, and controlling the atmosphere environment parameters includes controlling the oxygen content of the mixed gas to be within a preset range.

2. The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 1, wherein, Before the step of preparing the sulfide film on the surface of the medium substrate, the method further comprises cleaning the medium substrate, including: selecting a medium substrate with a designed size, cleaning the surface to remove dust particles, organic impurities and inorganic impurities, and the step of cleaning the surface comprises: placing the medium substrate in a vertical cleaning flower basket, and sequentially cleaning it in acetone solution, isopropanol solution and ultrapure water by using an ultrasonic cleaning machine for 10 minutes each time; blowing dry the two surfaces by using a high-purity argon gas gun, and placing the vertical cleaning flower basket in a blast drying oven at 110 DEG C for 5 minutes. 3.The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 1, wherein, The medium substrate is prepared by using a medium material with a light absorption coefficient lower than 0.05 in a target waveband, and the target waveband is any one of a visible light waveband, a short-wave infrared waveband, a medium-wave infrared waveband and a long-wave infrared waveband. 4.The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 3, wherein, The sulfide film is prepared by using a medium material with a light absorption coefficient lower than 0.08 in the target waveband. 5.The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 4, wherein, The step of preparing the sulfide film on the surface of the medium substrate comprises using thermal evaporation, magnetron sputtering, atomic layer deposition or chemical vapor deposition to prepare the sulfide film on the surface of the medium substrate. 6.The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 5, wherein, The thickness of the sulfide film is 100 nm-300 nm. 7.The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 1, wherein, The step of controlling the processing parameters of the laser direct writing processing space to perform laser-induced atomic exchange on the sulfide film comprises the following steps: adjusting the atmosphere composition of the laser direct writing processing system according to preset atmosphere environment parameters to obtain a preset atmosphere environment; obtaining a laser spot with a preset energy distribution pattern according to a preset processing pattern; generating laser spot scanning parameters according to the laser spot with the preset energy distribution pattern; performing laser-induced atomic exchange on the sulfide film according to the laser spot scanning parameters by using the laser spot in the preset atmosphere environment. 8.The laser-induced atomic-exchange-based chalcogenide photonic chip processing method according to claim 7, wherein, The step of controlling the atmosphere environment parameters includes controlling the oxygen content of the mixed gas to be within a preset range, and the oxygen content of the mixed gas is controlled to be 15%-30%.

9. A laser-induced atomic exchange-based chalcogenide photonic chip processing apparatus, characterized by, The application of the laser-induced atomic exchange-based chalcogenide photonic chip processing method according to any one of claims 1-8 comprises a laser light source, a beam adjustment system, a focusing system, a displacement system and an atmosphere control system, wherein: the laser light source is used to output a laser beam; the beam adjustment system is arranged before the focusing system at the outlet end of the laser light source, and is used to adjust the laser beam into a laser spot with a preset energy distribution pattern; the focusing system is arranged at the outlet end of the beam adjustment system, and is used to focus the laser beam and image the laser spot onto the surface of the sulfide film; and the displacement system is arranged at the outlet end of the focusing system, and is used to control the relative position between the laser spot and the sulfide film. The displacement system is arranged at the outlet end of the focusing system, and is used for placing the medium substrate provided with the sulfide film, and controlling the position of the medium substrate provided with the sulfide film through an electric signal. The atmosphere control system is used for changing the atmosphere environment parameters in which the sulfide film is located. 10.The laser-induced atomic-exchange-based chalcogenide photonic-chip processing apparatus according to claim 9, wherein, The processing observation system is arranged between the light beam adjustment system and the focusing system, and is used for observing the morphology of a processing area of the sulfide film.

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