An integrated micro-force and micro-displacement sensing chip based on tpp and semiconductor laser

Abstract

The application relates to the field of micro-nano sensing technology and discloses an integrated micro-force and micro-displacement sensing chip based on a TPP and a semiconductor laser, which comprises a high-power semiconductor FP laser, the two light-emitting surfaces of the high-power semiconductor FP laser are first natural cleavage surfaces and second natural cleavage surfaces, and the first natural cleavage surfaces and the second natural cleavage surfaces constitute a first FP resonant cavity; a Gaussian beam reconstruction wavefront reflecting surface is used to constitute a second FP resonant cavity with the second natural cleavage surface close to one side of the high-power semiconductor FP laser, the cavity length of the second FP resonant cavity is variable; and a first elastic deformation mechanism is connected with the Gaussian beam reconstruction wavefront reflecting surface. The FP laser is integrated with a deformable external cavity of two-photon 3D printing and an optimized reflecting surface, the precision measurement of force and displacement of a monitoring laser wavelength is realized, high integration, high sensitivity and excellent light coupling are achieved, and the sensing bottleneck is broken through.

Description

Technical Field

[0001] This invention relates to the field of micro-nano sensing technology, specifically to an integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor laser. Background Technology

[0002] Precise force measurement plays a fundamental role in various cutting-edge research fields. At the macroscopic level, accurate measurement of gravity in outer space helps in understanding the structure and evolution of the universe; at the microscopic level, precise understanding of intermolecular forces is key to in-depth research into chemical reaction mechanisms and biomolecular interactions. Currently, the main micro-force measurement technologies include atomic force microscopy (AFM) and specially developed micro / nano electromechanical systems (MEMS / NEMS) sensors. AFM utilizes the tip of a microcantilever beam to detect forces as low as tens of piconetons; however, such instruments are expensive, have complex detection systems, and suffer from poor electromagnetic compatibility. In practical applications, AFM requires sophisticated equipment and specialized operators, limiting its widespread use. MEMS / NEMS sensors are tiny in size and possess high sensitivity and response speed; however, they still lag behind applications requiring extremely high precision, such as piconet-level force measurements. Furthermore, they are susceptible to environmental factors, exhibiting shortcomings in environmental adaptability and stability.

[0003] Optical microforce sensors, including fiber Bragg grating (FBG) sensors, laser interferometers, and confocal optical sensors, are characterized by high sensitivity, capable of detecting extremely minute changes in physical quantities. By precisely measuring changes in parameters such as light intensity, phase, and wavelength, they can achieve high-precision measurement of minute forces. Optical signals are immune to electromagnetic interference, allowing them to operate stably in complex electromagnetic environments or scenarios with strong electromagnetic interference, ensuring the accuracy of measurement results. Optical sensors also possess good spatial resolution, enabling force measurement in micro- and nano-scale regions through focused beams, and can be used in research in many fields such as biomedicine, materials science, and micro / nano-fabrication.

[0004] Therefore, this invention proposes an integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor laser to address the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor lasers, solving the problem of developing micro-force and micro-displacement sensors that combine high sensitivity, high integration, miniaturization, and low cost.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser, comprising:

[0007] A high-power semiconductor FP laser, wherein the two light-emitting surfaces of the high-power semiconductor FP laser are respectively a first natural cleavage surface and a second natural cleavage surface, which constitute a first FP resonant cavity;

[0008] A Gaussian beam reconstructed wavefront reflecting surface is used to form a second FP resonant cavity with the second natural cleavage surface of the high-power semiconductor FP laser on its side. The cavity length of the second FP resonant cavity is variable.

[0009] The first elastic deformation mechanism is connected to the Gaussian beam reconstruction wavefront reflecting surface and is used to drive the Gaussian beam reconstruction wavefront reflecting surface to move under the action of external force, thereby changing the cavity length of the second FP resonant cavity.

[0010] A base is provided for fixing the high-power semiconductor FP laser and is connected to the first elastic deformation mechanism.

[0011] Preferably, the sensing chip further includes a stage, the high-power semiconductor FP laser is disposed on the upper surface of the stage, and a thin-film circuit is disposed on the upper surface of the stage. The thin-film circuit is connected to an external power supply for injecting current into the high-power semiconductor FP laser, i.e., lighting up the high-power semiconductor FP laser.

[0012] Preferably, the electrodes of the high-power semiconductor FP laser are connected to the thin-film circuit via gold wire bonding, and the light-emitting end face of the high-power semiconductor FP laser is connected to the coupling fiber via photonic wire bonding waveguide for low-loss output light coupling and input into a spectrometer for spectral analysis; a base is provided on the upper surface of the high-power semiconductor FP laser, the base is connected to one end of a first elastic deformation mechanism, and the other end of the first elastic deformation mechanism is connected to a Gaussian beam reconstruction wavefront reflecting surface, the first elastic deformation mechanism causing the position of the Gaussian beam reconstruction wavefront reflecting surface to shift along the transmission direction of the output light of the high-power semiconductor FP laser.

[0013] Preferably, the output lasing wavelength of the high-power semiconductor FP laser is... Simultaneously modulated by both the first FP resonant cavity and the second FP resonant cavity; when external force When the Gaussian beam reconstruction wavefront reflecting surface is acted upon, the first elastic deformation mechanism drives the Gaussian beam reconstruction wavefront reflecting surface to displace. This causes the cavity length of the second FP resonant cavity to change from the initial cavity length. Become The change in the cavity length of the second FP resonant cavity leads to the change in the output lasing wavelength of the high-power semiconductor FP laser. Measurable wavelength shift occurs. The external force With the displacement The relationship between them is: ,in The stiffness coefficient of the first elastic deformation mechanism; the measurable wavelength drift With the displacement There is a corresponding relationship between them, which can be achieved by measuring the wavelength drift. Determine the displacement and the external force .

[0014] Preferably, the Gaussian beam reconstruction wavefront reflecting surface has a reflecting surface. After the emitted beam of the high-power semiconductor FP laser has propagated a certain distance, the wavefront shape of the emitted beam has the characteristic of being non-rotationally symmetric. Therefore, the reflecting surface of the Gaussian beam reconstruction wavefront reflecting surface is specially constructed as a non-rotationally symmetric aspherical structure.

[0015] Preferably, the surface profile of the non-rotationally symmetric aspherical structure is described by the following formula: ;

[0016] in, , For the equation of the reflecting surface in and Major and minor axis coefficients in the direction, for , The curvature of the surface. The constant of the quadratic surface in the equation of the reflecting surface is... , , These are the coefficients of even-order terms of order 4, 6, and 8, respectively.

[0017] The specific curved surface profile of the aspherical structure is optimized and matched based on the actual equiphase surface shape when the emitted beam of the high-power semiconductor FP laser propagates to the location of the reflective surface. The aim is to ensure that the beam from the high-power semiconductor FP laser to the reflective surface can be accurately reflected back into the high-power semiconductor FP laser with maximum efficiency, thereby effectively coupling into and forming the second FP resonant cavity.

[0018] The coefficient , , , , , , The value is obtained by fitting the isophase point data of the emitted beam of the high-power semiconductor FP laser at a predetermined position.

[0019] This invention also provides a method for fabricating an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser, comprising:

[0020] S1. Provide a high-power semiconductor FP laser (4), the high-power semiconductor FP laser (4) having two opposing natural cleavage surfaces, one of which is a second natural cleavage surface (14) designated as a first laser end face for forming an external cavity, and the other of which is a first natural cleavage surface (12) designated as a second laser end face for light output;

[0021] S2. Using a two-photon polymerization process, a base (5), a first elastic deformation mechanism (6), and a Gaussian beam reconstruction wavefront reflector (7) are integrally manufactured on or relative to the high-power semiconductor FP laser (4), such that the base (5) is fixed to the high-power semiconductor FP laser (4), the first elastic deformation mechanism (6) connects the base (5) and the Gaussian beam reconstruction wavefront reflector (7), and the Gaussian beam reconstruction wavefront reflector (7) and the first laser end face of the high-power semiconductor FP laser (4) together constitute the second FP resonant cavity (15).

[0022] S3. A photonic wire bonding waveguide is fabricated using a two-photon polymerization process to optically couple the second laser end face of the high-power semiconductor FP laser to a coupling fiber.

[0023] Preferably, the step S1, in which the high-power semiconductor FP laser is stacked from bottom to top as a substrate, a buffer layer, a planar coupled waveguide layer, a lower confinement layer, a multiple quantum well layer, an upper confinement layer, an etch barrier layer, a waveguide layer, and a contact layer, includes:

[0024] S11. A buffer layer, a planar coupled waveguide layer and a lower confinement layer are sequentially grown on the substrate by metal-organic compound vapor deposition. Then, a multi-quantum well layer is grown on the lower confinement layer, an upper confinement layer is grown on the multi-quantum well layer, and then an etching barrier layer is grown above the upper confinement layer.

[0025] S12. Deposit InP above the corrosion barrier layer, and then grow the corrosion barrier layer, waveguide layer and contact layer in sequence.

[0026] S13. The waveguide layer and contact layer are etched to form ridges, and electrical isolation is etched to achieve partitioning. A front metal electrode is grown in the ridge region above the contact layer.

[0027] S14. Thinning and polishing the back side of the substrate, evaporating the back electrode and heating to obtain an alloy, and then cleaving the chip to obtain the high-power semiconductor quantum well FP laser.

[0028] Preferably, step S2, which involves manufacturing the base, the first elastic deformation mechanism, and the Gaussian beam reconstructed wavefront reflecting surface using a two-photon polymerization process, includes:

[0029] S21. Fix the high-power semiconductor FP laser to the processing stage, and apply photosensitive resin to the upper surface of the high-power semiconductor FP laser and the predetermined processing area near the end face of the first laser.

[0030] S22. Using optical imaging and image recognition algorithms, the predetermined printing position on the high-power semiconductor FP laser is accurately identified, and a preset three-dimensional digital model of the wavefront reflecting surface is reconstructed based on the base, the first elastic deformation mechanism and the Gaussian beam. The laser beam is aligned and a focused laser beam is used to selectively induce a polymerization reaction inside the photosensitive resin through the two-photon absorption effect, and the three-dimensional structure is constructed by scanning and exposing point by point, line by line and layer by layer.

[0031] S23. After exposure, the unpolymerized photosensitive resin is removed by development and then cleaned to expose and obtain the base, the first elastic deformation mechanism and the Gaussian beam reconstruction wavefront reflecting surface that are integrated with the high-power semiconductor FP laser.

[0032] Preferably, the step S3, which involves fabricating the photonic wire-bonded waveguide using a two-photon polymerization process, includes:

[0033] S31. Align the second laser end face of the high-power semiconductor FP laser with the input end of the coupling fiber and fix them on a common substrate. Then apply photosensitive resin to a predetermined processing area between the second laser end face and the input end of the coupling fiber.

[0034] S32. Using a high-magnification objective lens observation system and combined with an image recognition algorithm, identify the optical port position and normal direction of the second laser end face and the input end of the coupling fiber, and plan the three-dimensional path and geometry required for the photonic wire bonding waveguide accordingly.

[0035] S33. According to the planned path and geometry, a focused laser beam is used to selectively initiate a polymerization reaction inside the photosensitive resin through the two-photon absorption effect, thereby completing the exposure forming of the photonic wire bonded waveguide.

[0036] S34. After exposure, the unpolymerized photosensitive resin is removed by a development process to expose and obtain the photonic wire bonding waveguide connecting the second laser end face of the high-power semiconductor FP laser and the input end of the coupling optical fiber.

[0037] This invention provides an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser. It offers the following advantages:

[0038] 1. This invention employs a sensing solution that integrates a high-power semiconductor FP laser with a deformable external cavity created by two-photon polymerization 3D printing. This achieves the technical effect of precisely detecting minute displacements and external forces by monitoring changes in the laser's lasing wavelength. Compared to existing sensing systems with discrete components and complex optical path coupling, this invention overcomes the shortcomings of low integration, difficult system calibration, and potentially poor alignment stability.

[0039] 2. This invention employs a reflective surface manufacturing scheme that combines laser output wavefront reconstruction optimization design with two-photon polymerization 3D printing technology. This achieves the precise fabrication of complex curved surface reflectors that match the laser beam wavefront, thereby significantly improving optical feedback efficiency and laser operational stability. Compared to existing technologies that commonly use standard planar or spherical reflectors, this invention overcomes the shortcomings of low optical coupling efficiency and poor sensing signal quality caused by beam mode mismatch.

[0040] 3. This invention employs two-photon polymerization technology to integrate key sensing microstructures such as the base, elastic deformation mechanism, and wavefront reconstruction reflector onto a laser chip in situ, achieving a highly integrated, high-precision aligned, and mechanically superior integrated sensing device. Compared to traditional micro / nano device manufacturing processes that rely on separate fabrication of multiple components followed by precise assembly, this invention overcomes the shortcomings of cumbersome processes, susceptibility to assembly errors, and difficulty in achieving device miniaturization and high-precision alignment.

[0041] 4. This invention employs a high-power semiconductor FP laser coupled with a deformable external resonant cavity customized using two-photon polymerization technology to form a dual-cavity system. By monitoring the laser output wavelength drift, it directly inverts external force or displacement, achieving high sensitivity, high resolution measurement, and simplified signal demodulation. Compared to existing sensing mechanisms that rely on changes in light intensity, capacitance, or other indirect physical quantity conversions, this invention overcomes the shortcomings of potentially nonlinear responses, susceptibility to environmental noise interference, and relatively complex signal processing.

[0042] 5. This invention employs an integrated optical sensing scheme that deeply integrates a high-power semiconductor FP laser, a two-photon 3D-printed deformable external cavity, and an optimized wavefront reconstructed reflector, achieving the technical effect of constructing a miniaturized, high-precision, and high-sensitivity micro-force and micro-displacement sensing system. Compared to existing technologies that simply combine or separately apply the above-mentioned technical elements, failing to fully leverage their synergistic advantages, this invention overcomes the shortcomings in improving integration, optimizing optical coupling efficiency, and breaking through sensing performance bottlenecks. Attached Figure Description

[0043] Figure 1 This is a perspective view of the device of the present invention;

[0044] Figure 2 This is a schematic diagram of the micro-force and micro-displacement test according to the present invention;

[0045] Figure 3 This is a schematic diagram showing the slope of the fitted line of the present invention;

[0046] Figure 4 This is a schematic diagram of the spring stress of the present invention. Figure 1 ;

[0047] Figure 5 This is a schematic diagram of the spring stress of the present invention. Figure 2 ;

[0048] Figure 6 This is a schematic diagram of the mode field distribution of the laser's TE fundamental mode according to the present invention;

[0049] Figure 7 This is a schematic diagram of the high-power semiconductor quantum well FP laser of the present invention;

[0050] Figure 8 This is a schematic diagram of the second elastic deformation mechanism of the present invention.

[0051] Among them, 1. Spectrometer; 2. Coupled optical fiber; 3. Photonic wire bonded waveguide; 4. High-power semiconductor FP laser; 5. Base; 6. First elastic deformation mechanism; 7. Gaussian beam reconstruction wavefront reflecting surface; 8. Thin film circuit; 9. Stage; 10. Gold wire bonding; 11. External power supply; 12. First natural cleavage surface; 13. First FP resonant cavity; 14. Second natural cleavage surface; 15. Second FP resonant cavity; 16. First reflection spectrum; 17. Second reflection spectrum; 18. First fitted straight line; 19. Rectangular cross-section width; 20. Rectangular cross-section thickness; 21. Natural length; 22. Spring radius; 23. Second fitted straight line; 24. Equiphase point; 25. Reflecting surface morphology; 26. Second elastic deformation mechanism. Detailed Implementation

[0052] The technical solutions in the embodiments 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, and 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.

[0053] Please see Figure 1-6 This invention provides an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser, comprising:

[0054] A high-power semiconductor FP laser 4, wherein the two light-emitting surfaces of the high-power semiconductor FP laser 4 are respectively a first natural cleavage surface 12 and a second natural cleavage surface 14, which constitute a first FP resonant cavity 13;

[0055] Specifically, the high-power semiconductor FP laser 4 serves as the light source for the chip. The high-power semiconductor FP laser 4 has two opposing light-emitting surfaces, namely a first natural cleavage surface 12 and a second natural cleavage surface 14. These two natural cleavage surfaces themselves constitute a Fabry-Perot (FP) resonant cavity, namely the first FP resonant cavity 13. In a specific embodiment, the physical length of the first FP resonant cavity 13 (…) It can be 500µm;

[0056] The Gaussian beam reconstruction wavefront reflecting surface 7 and the second natural cleavage surface 14 of the high-power semiconductor FP laser 4 are arranged opposite each other, together forming a second Fabry-Perot resonator, namely the second FP resonator 15. The cavity length of the second FP resonator 15 is variable. In a specific embodiment, its initial static cavity length ( The diameter can be 75µm. The surface profile of the reconstructed wavefront reflector 7 is specially designed to optimize reflection efficiency.

[0057] One end of the first elastic deformation mechanism 6 is connected to the Gaussian beam reconstruction wavefront reflecting surface 7, and the other end is connected to the base 5. Its main function is to drive the Gaussian beam reconstruction wavefront reflecting surface 7 to shift along the transmission direction of the output light of the high-power semiconductor FP laser 4 when an external force is applied to it, thereby precisely changing the cavity length of the second FP resonant cavity 15.

[0058] Gaussian beam reconstruction wavefront reflecting surface 7, which is used to form a second FP resonant cavity 15 with the second natural cleavage surface 14 on the side of the high-power semiconductor FP laser 4, and the cavity length of the second FP resonant cavity 15 is variable.

[0059] The first elastic deformation mechanism 6 is connected to the Gaussian beam reconstruction wavefront reflecting surface 7 and is used to drive the Gaussian beam reconstruction wavefront reflecting surface 7 to move under the action of external force, thereby changing the cavity length of the second FP resonant cavity 15.

[0060] Base 5, which is used to fix the high-power semiconductor FP laser 4 and is connected to the first elastic deformation mechanism 6;

[0061] Specifically, the base 5 is directly fixed to the upper surface of the high-power semiconductor FP laser 4 and connected to one end of the first elastic deformation mechanism 6, providing stable support and positioning reference for the elastic mechanism and the reflective surface.

[0062] The sensing chip also includes a stage 9. The high-power semiconductor FP laser 4 is disposed on the upper surface of the stage 9. A thin film circuit 8 is disposed on the upper surface of the stage 9. The thin film circuit 8 is connected to an external power supply 11 and is used to inject current into the high-power semiconductor FP laser 4, that is, to light up the high-power semiconductor FP laser 4.

[0063] Specifically, a high-power semiconductor FP laser 4 is disposed on the upper surface of the stage 9, and a thin-film circuit 8 is disposed on the upper surface of the stage 9 and connected to the electrodes of the high-power semiconductor FP laser 4 through gold wire bonding 10; an external power supply 11 is connected to the thin-film circuit 8 and is used to inject current into the high-power semiconductor FP laser 4 to realize the electric pumping and lighting of the high-power semiconductor FP laser.

[0064] The electrodes of the high-power semiconductor FP laser 4 are connected to the thin-film circuit 8 via gold wire bonding 10. The light-emitting end face of the high-power semiconductor FP laser 4 is connected to the coupling fiber 2 via photonic wire bonding waveguide 3 for low-loss output light coupling and input into the spectrometer 1 for spectral analysis. A base 5 is provided on the upper surface of the high-power semiconductor FP laser 4. The base 5 is connected to one end of the first elastic deformation mechanism 6. The other end of the first elastic deformation mechanism 6 is connected to the Gaussian beam reconstruction wavefront reflecting surface 7. The first elastic deformation mechanism 6 causes the position of the Gaussian beam reconstruction wavefront reflecting surface 7 to be displaced along the transmission direction of the output light of the high-power semiconductor FP laser 4.

[0065] Specifically, in the optical coupling output section: the output end face of the high-power semiconductor FP laser 4 is connected to the external coupling fiber 2 via a photonic wire bonding waveguide 3. This photonic wire bonding waveguide 3 is used to couple the optical output of the high-power semiconductor FP laser 4 into the optical fiber 2 with low loss, and then further input it into the spectrometer 1 for spectral analysis.

[0066] Please see Figures 2-6In this embodiment, the mechanism by which the integrated micro-force and micro-displacement sensing chip achieves its sensing function, and the optimized design of its core optical components, together form the basis for high-sensitivity micro-force and micro-displacement measurement. This mechanism relies on the modulation of the output characteristics of the high-power semiconductor FP laser 4 by a precisely controlled dual Fabry-Perot (FP) resonant cavity system.

[0067] Specifically, the core of the optical system of the sensing chip includes two interacting FP resonant cavities. One is the first FP resonant cavity 13 inherent in the high-power semiconductor FP laser 4 itself. This first FP resonant cavity 13 is jointly formed by two opposing natural cleavage surfaces of the high-power semiconductor FP laser 4, namely the first natural cleavage surface 12 and the second natural cleavage surface 14. This first FP resonant cavity 13 has a defined physical cavity length, denoted in this embodiment as _____. Secondly, there is an externally formed second FP resonant cavity 15. This second FP resonant cavity 15 is jointly formed by the second natural cleavage surface 14 of the high-power semiconductor FP laser 4 and the Gaussian beam reconstruction wavefront reflecting surface 7 disposed outside and opposite to it. The initial static cavity length of this second FP resonant cavity 15 when it is not subjected to external force or displacement is denoted as in this embodiment. For example, in a specific design, this initial static cavity length It can be set to 75µm.

[0068] Typically, the final output lasing wavelength of the high-power semiconductor FP laser 4 is denoted as... The lasing mode selection of the high-power semiconductor FP laser 4 is not solely determined by its internal first FP resonator 13, but is modulated by the dual-cavity system composed of the first FP resonator 13 and the external second FP resonator 15. This dual-cavity coupling effect makes the lasing mode selection of the high-power semiconductor FP laser 4 highly sensitive to changes in the parameters of the external resonator (i.e., the second FP resonator 15), especially small variations in its cavity length.

[0069] When there is an external force When applied to the Gaussian beam reconstruction wavefront reflecting surface 7, the first elastic deformation mechanism 6 connected to the Gaussian beam reconstruction wavefront reflecting surface 7 will undergo corresponding elastic deformation due to the force. This elastic deformation will drive the Gaussian beam reconstruction wavefront reflecting surface 7 to undergo a small displacement along the optical axis direction (i.e., the laser emission direction) of the high-power semiconductor FP laser 4. This displacement is denoted as in this embodiment. .

[0070] This displacement This directly alters the effective optical cavity length of the second FP resonator 15, changing it from its initial cavity length. Change to a new cavity length ( The external force and the resulting displacement The relationship between them, within the elastic working limit of the first elastic deformation mechanism 6, can generally be approximated as a linear relationship, that is: Here, The equivalent stiffness coefficient represents the first elastic deformation mechanism 6, which depends primarily on the material properties and geometry of the elastic mechanism.

[0071] This change in the cavity length of the second FP resonator 15 will cause a corresponding change in the effective reflection spectrum or mode loss spectrum of the entire dual-cavity coupled system. The direct result is that the output lasing wavelength of the high-power semiconductor FP laser 4 will change. This will result in a corresponding, precisely measurable wavelength shift, denoted as... In a specific exemplary scenario, when an external force causes displacement... Changes, for example When the lasing wavelength changes from 0 to -100nm, It may change linearly from 1539.876 nm to 1539.784 nm. This lasing wavelength With displacement The relationship between them usually exhibits good linearity, and their displacement sensing sensitivity (i.e. The sensitivity can be accurately characterized by the slope of the straight line obtained by linearly fitting the experimental data; for example, the sensitivity value can be 0.0184 nm / nm.

[0072] Therefore, the wavelength shift of the output light from the high-power semiconductor FP laser 4 can be measured using an external spectral analysis device, such as spectrometer 1. Real-time monitoring and high-precision measurement are performed, combined with the wavelength drift obtained in advance through experimental calibration or theoretical calculation. With the displacement The characteristic response relationship between them can be used to accurately deduce the minute displacement of the Gaussian beam reconstructed wavefront reflecting surface 7. After further determining the displacement Subsequently, if the stiffness coefficient of the first elastic deformation mechanism 6 If the force is known or has been obtained through calibration, then the relationship between force and displacement can be applied according to the above formula. Calculate the external force that caused the displacement. Size.

[0073] The first elastic deformation mechanism 6 is specifically implemented as a rectangular cross-section cylindrical helical compression spring, as an example for explanation. The structural parameters of this spring, such as the width of the rectangular cross-section constituting the spring wire... 19. Thickness of rectangular section 20. Effective number of working turns of the spring The number of coils is 1, and the natural length of the spring when it is not under force. 21, both can be precisely controlled and spring radius can be achieved through two-photon polymerization (TPP) micro / nano manufacturing processes. 22. The finite element method (FEM) can be used to analyze springs with specific geometric parameters and material properties under different external forces. Stress distribution and deformation under action Calculations are performed. Based on such simulation data or data obtained through experimental measurements, a fitting force can be obtained. With displacement The relationship curve is used to obtain the spring constant for this specific spring design. For example, in one possible spring design, its spring constant... It can reach 83.4 pN / nm. Based on this stiffness coefficient... and the aforementioned displacement sensing sensitivity This allows for further calculation of the micro-force measurement sensitivity of the sensor chip. (Right now For example, the sensitivity of this microforce measurement can reach the order of 0.22 nm / nN.

[0074] To ensure the efficient and stable operation of the wavelength modulation-based sensing mechanism and to achieve high-sensitivity measurements, the beam emitted from the high-power semiconductor FP laser 4 must be able to efficiently couple back to itself to form a high-quality second FP resonant cavity 15. This is the fundamental reason for the optimized design of the Gaussian beam reconstruction wavefront reflector 7.

[0075] Generally, the wavefront shape of beams emitted from high-power semiconductor FP lasers, especially edge-emitting lasers like the high-power semiconductor FP laser 4 described in this embodiment, often exhibits non-rotational symmetry after propagating a certain distance. This asymmetry mainly stems from the different confinement capabilities of the internal resonant cavity structure of the high-power semiconductor FP laser 4 in the directions parallel and perpendicular to the PN junction plane, as well as the anisotropy of the active region gain medium itself. Typically, the emitted beam from the high-power semiconductor FP laser 4 has different beam waist radii, different far-field divergence angles, and possible astigmatism in the horizontal and vertical directions. For example, its output beam may have a larger near-field mode size in the horizontal direction, corresponding to a smaller far-field divergence angle; while in the vertical direction, the near-field mode size may be smaller, corresponding to a larger far-field divergence angle.

[0076] Electric field distribution of this asymmetric Gaussian beam Under certain conditions, it can be approximately described by the following formula: ;

[0077] in: For the light field at the initial position (e.g.) The amplitude of the vibration at (location); and The beams are respectively in Along (e.g., the light-emitting end face of a laser) direction and The waist radius in the direction; and These represent the distances of the light beam as it travels. along direction and Radius of the light spot in the direction; The wavenumber of the light beam in the propagation medium; This represents the distance along the principal direction of the beam propagation. and respectively along the beam direction and The Rayleigh length in the direction represents the collimation region of a Gaussian beam; and These represent the distances of the light beam as it travels. along direction and Radius of curvature of the directional equivalent wavefront.

[0078] If a conventional plane mirror or a simple rotationally symmetric spherical mirror is used as the external mirror constituting the second FP resonant cavity 15, i.e., the Gaussian beam reconstruction wavefront reflecting surface 7, then due to the inherent asymmetric divergence characteristics of the laser beam and possible wavefront distortions (such as astigmatism), only a small portion of paraxial rays near the beam center can be effectively reflected and coupled back into the resonant cavity (i.e., the first FP resonant cavity 13) of the high-power semiconductor FP laser 4. Most off-axis rays will be lost due to angle mismatch or mode mismatch, resulting in a poor match between the overall mode field distribution of the reflected light and the inherent mode of the high-power semiconductor FP laser 4, thus causing low optical coupling efficiency. This inefficient coupling not only significantly increases the round-trip loss of the second FP resonant cavity 15, but may also adversely affect the operating characteristics of the laser 4, such as increasing its lasing threshold current, reducing output power, and even affecting the stability of its lasing mode, thereby reducing the overall sensitivity and accuracy of the sensing.

[0079] To overcome this technical challenge and maximize optical feedback efficiency, in this embodiment, the reflecting surface of the Gaussian beam reconstruction wavefront reflecting surface 7 is specially designed and constructed as a non-rotationally symmetric aspherical structure. The core design idea is to ensure that the three-dimensional surface profile of the Gaussian beam reconstruction wavefront reflecting surface 7 accurately matches or highly approximates the actual equiphase surface shape of the emitted beam from the high-power semiconductor FP laser 4 when it propagates to the location of the reflecting surface.

[0080] The surface profile of the non-rotationally symmetric aspherical structure That is, the surface height varies with the lateral coordinate in a Cartesian coordinate system with the intersection of the optical axis and the surface as the origin. and The relationship between the changes shows the morphology 25 of the reflecting surface reconstructed based on the equiphase point 24, and the surface equation of the reflecting surface is reconstructed by fitting the equiphase point 24: ;

[0081] in, , For the equation of the reflecting surface in and Major and minor axis coefficients in the direction, for , The curvature of the surface. The constant of the quadratic surface in the equation of the reflecting surface is... , , These are the coefficients for even-order terms of the 4th, 6th, and 8th orders, respectively. These higher-order coefficients are used to further refine the basic quadratic surface, enabling the reflecting surface to more accurately fit complex or non-ideal wavefront shapes and effectively compensate for possible higher-order aberrations.

[0082] In one possible implementation, the coefficients of the above aspherical equations (e.g.) , , , , , , The determination of the precise value of (etc.) is a process based on detailed analysis and optimization calculation of the actual output beam characteristics of the high-power semiconductor FP laser 4.

[0083] This process typically includes: First, acquiring three-dimensional light field distribution data, especially its isophase surface data, of the emitted beam from the high-power semiconductor FP laser 4 when it propagates in free space to the predetermined Gaussian beam reconstruction wavefront reflector 7 at its designed position, using sophisticated optical simulation tools or high-resolution wavefront sensing experimental techniques. Then, extracting a series of representative spatial coordinate points from the calculated or measured isophase surface. Finally, using a nonlinear surface fitting algorithm, the coordinate data of these sampling points are used as target data to fit the aforementioned aspherical equations, and a set of coefficient values ​​that best describe the shape of the isophase surface is obtained through an iterative optimization process. For example, in the initial cavity length of the second FP resonant cavity 15... Given a setting of 75µm, a set of exemplary aspherical coefficients that may be obtained through this type of fitting process are as follows: .

[0084] By employing a non-rotationally symmetric aspherical surface, custom-designed based on the wavefront characteristics of the actual emitted beam from the high-power semiconductor FP laser 4, as the Gaussian beam reconstruction wavefront reflecting surface 7, it is ensured that the majority of the energy of the beam emitted from the high-power semiconductor FP laser 4 and reaching the Gaussian beam reconstruction wavefront reflecting surface 7 can be precisely reflected back into the first FP resonant cavity 13 of the high-power semiconductor FP laser 4 in a near-original path return manner, and effectively coupled into it, thereby forming the second FP resonant cavity 15 with high quality. This optimized design not only significantly improves the efficiency of optical feedback and effectively reduces the round-trip loss of the external resonant cavity, but also helps maintain stable lasing of the high-power semiconductor FP laser 4 in the desired single longitudinal mode or a few specific longitudinal modes, and enhances the sensitivity of the output wavelength of the high-power semiconductor FP laser 4 to changes in the cavity length of the external resonant cavity 15. This provides a solid optical foundation and performance guarantee for achieving high-precision and high-stability micro-force and micro-displacement sensing.

[0085] Please see Figure 7 In this embodiment, the fabrication method of the integrated micro-force and micro-displacement sensing chip mainly includes the fabrication of a high-power semiconductor FP laser 4, and the subsequent integration of key optical and mechanical microstructures using two-photon polymerization (TPP) technology. The specific technical implementation is as follows:

[0086] In this embodiment, the steps for providing the high-power semiconductor FP laser 4 are described in detail. The fabrication of the high-power semiconductor FP laser 4 is the foundation of the entire sensor chip manufacturing process. Its typical structural form is a multilayer heterojunction structure.

[0087] In the fabrication process, the first step is the epitaxial growth of semiconductor materials. Specifically, on a selected suitable substrate, such as indium phosphide (InP) substrate, precision epitaxial growth techniques such as metal-organic chemical vapor deposition (MOCVD) are used to sequentially grow materials according to the pre-designed device structure and the required thickness of each functional layer. These functional layers typically include, from the substrate upwards: a buffer layer, which improves the crystal quality of subsequent epitaxially grown layers; a planar coupled waveguide layer, used to control the waveguide mode and achieve effective mode coupling; a lower confinement layer, which confines the distribution of charge carriers and optical field in the active region; a multiple quantum well (MQW) active layer, which is the core region for laser generation and amplification; an upper confinement layer, which works in conjunction with the lower confinement layer to effectively confine charge carriers and optical field within the MQW active layer region; and a first etch stop layer, used to provide selective etch stop in subsequent etching processes.

[0088] Subsequently, deposition continues above the first etch barrier layer to form the superstructure. This process involves depositing another layer of indium phosphide (InP) material, followed by the sequential growth of a second etch barrier layer, a waveguide layer that will be used to form a ridge waveguide structure in subsequent processes, and a heavily doped contact layer designed to form a low-resistance ohmic contact.

[0089] Next, the chip is fabricated using microfabrication steps. Utilizing photolithography and etching techniques from standard semiconductor processes, the upper waveguide layer and contact layer are patterned and etched to form a ridge waveguide structure with specific width and height. Simultaneously, electrically isolated zones within the device are created through precisely controlled etching and other methods to allow for precise control of current injection into specific areas of the active region. After the ridge waveguide structure is fabricated, a front-side metal electrode is grown on the contact layer at the top of the ridge waveguide using metallization processes such as electron beam evaporation and photolithographic lift-off.

[0090] Finally, preparations for back-side processing and packaging are performed. The back side of the substrate with the front-side structure is thinned to reduce the device thickness and polished to obtain a flat surface. Then, a back-side metal electrode is formed on the thinned and polished back side of the substrate using an evaporation process. To ensure good ohmic contact between the metal electrode and the semiconductor material, alloying processes such as rapid thermal annealing (RTA) are typically required. After completing all the above steps, the entire wafer is cleaved according to a predetermined chip size, dividing it into individual laser chip strips or independent laser units. The cleaving surfaces naturally formed during this cleaving process constitute the first natural cleaving surface 12 and the second natural cleaving surface 14 of the high-power semiconductor FP laser 4. These two opposing natural cleaving surfaces with a certain reflectivity together constitute the first FP resonant cavity 13 inside the high-power semiconductor FP laser 4. One of the cleavage surfaces, such as the second natural cleavage surface 14, is designed to be used together with the external Gaussian beam reconstruction wavefront reflecting surface 7 to form the first laser end face of the second FP resonant cavity 15; while the other cleavage surface, such as the first natural cleavage surface 12, can be used as the light output end face of the high-power semiconductor FP laser 4, i.e., the second laser end face.

[0091] In this embodiment, the TPP integrated manufacturing process of the base 5, the first elastic deformation mechanism 6, and the Gaussian beam reconstruction wavefront reflecting surface 7 is described in detail. After obtaining the fabricated high-power semiconductor FP laser 4, the base 5, the first elastic deformation mechanism 6, and the Gaussian beam reconstruction wavefront reflecting surface 7 are manufactured in situ and integrally at a specific location on the high-power semiconductor FP laser 4 using two-photon polymerization (TPP) laser direct-write 3D printing technology.

[0092] Specifically, the pre-fabricated high-power semiconductor FP laser 4 chip is first precisely fixed onto the processing stage 9 of the two-photon polymerization 3D printing equipment using a suitable clamp or adhesive method. Then, liquid photosensitive resin (also known as photoresist) is applied to the upper surface of the high-power semiconductor FP laser 4 and the predetermined processing area near the second natural cleavage surface 14, which is intended to be used as an external cavity mirror, using methods such as drop casting or spin coating. It is essential to ensure that all areas to be processed are completely and uniformly covered by the photosensitive resin.

[0093] Secondly, precise alignment and processing parameter settings are performed before exposure. The pre-designed three-dimensional digital models of the base 5, the first elastic deformation mechanism 6, and the Gaussian beam reconstruction wavefront reflecting surface 7 are imported into the control software system of the TPP device. Utilizing the high-magnification objective lens and high-resolution camera system integrated into the TPP device, combined with precision imaging methods such as confocal imaging or layer-by-layer imaging, and supplemented by image recognition algorithms targeting specific structures on the laser chip, the actual spatial position and orientation of the fixed high-power semiconductor FP laser 4 are accurately identified and positioned. This step is crucial to ensure that the three-dimensional microstructure subsequently printed using TPP technology can be accurately positioned on the predetermined location on the laser chip and maintain the designed relative relationship with relevant parts of the laser (such as the second natural cleavage surface 14). After precise positioning, various processing parameters of the TPP device are set based on factors such as the optical and chemical properties of the selected photosensitive resin, the desired structural accuracy, and processing efficiency. These parameters include the output power of the femtosecond laser, the scanning speed of the laser focus within the photosensitive resin, and the scanning path planning strategy.

[0094] Then, a two-photon polymerization exposure process is performed. An objective lens with a high numerical aperture (NA) focuses an ultrafast femtosecond laser beam into a tiny volume (i.e., a voxel) within the photosensitive resin, which is diffraction-limited. At this laser focal point, due to the extremely high instantaneous photon density, the photosensitive resin molecules can simultaneously absorb two incident photons, thereby being excited and initiating a local chemical polymerization reaction. The control system drives the laser focal point or sample stage to perform a precise point-by-point, line-by-line, and layer-by-layer scan of the photosensitive resin according to the geometry defined by the previously imported three-dimensional digital model. Due to the nonlinear characteristics of two-photon absorption, the light intensity at the laser focal point is sufficient to effectively induce the polymerization reaction of the photosensitive resin; outside the focal point, even if laser light passes through, its intensity is insufficient to induce two-photon absorption, so the photosensitive resin in these areas will remain in an unpolymerized liquid or gel state. In this way, the designed three-dimensional microstructure is precisely constructed step by step at the predetermined position of the high-power semiconductor FP laser 4 chip, including the base 5 which is firmly fixed to the upper surface of the laser, the first elastic deformation mechanism 6 which is connected to the base 5 at one end and has a specific designed elastic coefficient, and the Gaussian beam reconstruction wavefront reflecting surface 7 which is connected to the elastic mechanism at the other end and has a specific aspherical profile.

[0095] Finally, the development and post-processing steps are performed. After the two-photon polymerization exposure process is completed, the laser chip with the exposed structure is removed from the TPP equipment and immersed in a specific developing solution. The choice of developing solution depends on the chemical properties of the photosensitive resin used, and its function is to dissolve and completely remove the photosensitive resin parts that have not been exposed to the laser for polymerization. The three-dimensional microstructures that have been exposed to the laser and polymerized and hardened are preserved intact because they are insoluble in the developing solution, thus initially revealing the designed morphology. To avoid structural collapse, deformation, or damage to these delicate three-dimensional microstructures, especially some high aspect ratio or cantilever structures, due to excessive liquid surface tension during the drying process with traditional solvents (such as isopropanol IPA), a preferred strategy is to use a special cleaning agent with low surface tension, such as methyl nonafluorobutyl ether, for the final cleaning and drying steps. Through the above steps, the base 5, the first elastic deformation mechanism 6, and the Gaussian beam reconstruction wavefront reflecting surface 7, which are precisely aligned with and integrated with the high-power semiconductor FP laser 4, are obtained.

[0096] In this embodiment, the TPP manufacturing steps of the photonic wire-bonded waveguide 3 are described in detail. To achieve high-efficiency optical coupling between the high-power semiconductor FP laser 4 and external optical components, such as the coupling fiber 2, the polymer photonic wire-bonded waveguide 3 can also be manufactured using two-photon polymerization (TPP) technology.

[0097] Specifically, the first step is to align and fix the optical components to be connected. The components to be optically interconnected via the PWB waveguide—namely, the partially fabricated sensor chip with an integrated laser module 4, and the end of a coupling fiber 2 for optical signal input / output—are adjusted to their predetermined relative positions and orientations using a high-precision positioning platform, and then securely fixed to a common substrate or special fixture. This step ensures that a suitable gap, meeting the requirements of the PWB manufacturing process, is maintained between the output facet of the high-power semiconductor FP laser 4 and the input facet of the coupling fiber (2). Subsequently, a special photosensitive resin specifically designed for PWB waveguide fabrication is applied to the predetermined processing area between the laser output facet and the fiber input facet, ensuring that the entire three-dimensional path for forming the waveguide is completely covered by the photosensitive resin.

[0098] Secondly, the optical ports are accurately identified and the waveguide path is planned. Using the high-magnification objective lens observation system integrated into the TPP device, methods such as confocal imaging or layer-by-layer imaging can be employed. Combined with image recognition algorithms designed for specific waveguide structures or end-face features (such as fiber cores and ridge waveguide edges), the precise spatial positions of the output end face of the high-power semiconductor FP laser 4 and the input end face (mainly the fiber core position) of the coupling fiber 2, the size of the effective optical ports, and the normal directions of their respective end faces can be accurately identified. Based on this accurately identified information, and according to the design principle of optimizing optical coupling efficiency, the three-dimensional spatial path and geometry required for the PWB waveguide 3 connecting these two optical ports are planned in the control software of the TPP device. This path and shape can be designed as a straight line, a tapered gradient, a curved shape, or a more complex combination of free-form surfaces, depending on specific requirements.

[0099] Next, the TPP exposure forming process for the PWB waveguide is performed. Utilizing the high-precision motion control system within the TPP system, the laser focus is driven to precisely scan and expose within the applied photosensitive resin according to the pre-planned three-dimensional path and geometry. The laser beam output from the femtosecond laser is focused to the starting position where the waveguide needs to be formed. The laser focus then moves along the planned path within the photosensitive resin, selectively polymerizing the resin through the two-photon absorption effect, thereby completing the exposure forming of the entire polymer waveguide structure in three-dimensional space.

[0100] Finally, development and post-processing are performed. After the exposure process of the PWB waveguide is completed, it also needs to go through a development process. The component with the exposed PWB structure is immersed in a suitable developer to wash away the photosensitive resin that has not been laser-polymerized, while the PWB photonic wire-bonded waveguide 3, which is made of polymer and precisely connects the output end face of the high-power semiconductor FP laser 4 to the input end face of the coupling fiber 2, is retained. The PWB waveguide manufactured in situ using TPP technology can precisely adapt to the actual position and shape of the two optical ports to be connected and can be designed as a gradient structure with mode conversion function.

[0101] Please see Figure 8 This invention also provides a second elastic deformation mechanism 26 as a possible alternative to the first elastic deformation mechanism 6. All other manufacturing processes and measurement principles remain the same.

[0102] Working principle: The output lasing wavelength of the high-power semiconductor FP laser 4 Simultaneously, it is modulated by both its own first FP resonant cavity 13 and the external second FP resonant cavity 15. This multi-cavity structure makes the laser's lasing wavelength highly sensitive to changes in the cavity length of the external resonant cavity (second FP resonant cavity 15).

[0103] When there is an external force When applied to the Gaussian beam reconstruction wavefront reflecting surface 7, the first elastic deformation mechanism 6 deforms, driving the Gaussian beam reconstruction wavefront reflecting surface 7 to produce a small displacement along the transmission direction of the laser output light. .external force With displacement The relationship between them follows Hooke's Law, that is: ,in This is the equivalent stiffness coefficient of the first elastic deformation mechanism 6. When external force... When the direction is pointed towards the high-power semiconductor FP laser 4, the displacement It is negative; conversely, when the direction of the external force is away from the high-power semiconductor FP laser 4, It is a positive value; this displacement The cavity length of the second FP resonant cavity 15 was directly changed, from the initial cavity length. Become The change in the cavity length of the second FP resonator 15 will cause a change in the effective reflection spectrum of the entire dual-cavity system, which in turn will affect the output lasing wavelength of the high-power semiconductor FP laser 4. A wavelength shift that can be precisely measured occurs. ;wherein, spectral line 15 indicates the first FP resonant cavity. 13 shows the reflection spectrum when acting alone, and the first reflection spectral line 16 illustrates the second FP resonant cavity. The reflection spectrum of line 15 when acting alone is shown, while the second reflection spectral line 17 represents the overall reflection spectrum when both cavities are working together. Lasers typically lasing at the wavelength with the highest reflectivity (or lowest equivalent loss) in the overall reflection spectrum. For example, in a specific state, the lasing wavelength might be 1539.876 nm. When external forces cause... When changes occur, for example From 0 to -100nm, lasing wavelength It may change linearly from 1539.876 nm to 1539.784 nm. This lasing wavelength With displacement The relationship between them usually exhibits good linearity, and their sensitivity (i.e., The slope of the first fitted line 18 can be accurately characterized, such as 0.0184 nm / nm.

[0104] Therefore, the drift of the laser output lasing wavelength is monitored in real time by an external spectrometer 1. Then it can be based on the pre-calibrated and The corresponding relationship allows for the precise deduction of the displacement of the Gaussian beam reconstructing the wavefront reflecting surface 7. Furthermore, this is combined with the known or pre-calibrated stiffness coefficient of the first elastic deformation mechanism 6. It can be done through the formula Calculate the external force applied to the reconstructed wavefront reflecting surface 7 of the Gaussian beam. Taking the first elastic deformation mechanism 6 as an example, which is a cylindrical helical compression spring with a rectangular cross-section, its structural parameters are as follows: rectangular cross-section width... 19. Thickness of rectangular section 20. Number of turns Number of circles is 1, natural length 21 and spring radius All of these parameters, including those of parameter 22, can be precisely controlled using the TPP process; different external forces can be calculated through finite element simulation analysis (FEM). Stress distribution and deformation of spring under action Based on simulation, through fitting and The spring constant can be obtained from the second fitted straight line 23 in the relationship. ,For example pN / nm. Based on this, the micro-force measurement sensitivity of the sensor chip can be calculated. For example, 0.22nm / nN.

[0105] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor laser, characterized in that, include: A high-power semiconductor FP laser (4) has two light-emitting surfaces on its two sides, namely a first natural cleavage surface (12) and a second natural cleavage surface (14), which together form a first FP resonant cavity (13). A Gaussian beam reconstructed wavefront reflecting surface (7) is used to form a second FP resonant cavity (15) with the second natural cleavage surface (14) of the high-power semiconductor FP laser (4) on its side. The cavity length of the second FP resonant cavity (15) is variable. The Gaussian beam reconstruction wavefront reflecting surface (7) has a reflecting surface. After the outgoing beam of the high-power semiconductor FP laser (4) propagates a certain distance, the outgoing beam wavefront shape has the characteristic of non-rotational symmetry. Therefore, the reflecting surface of the Gaussian beam reconstruction wavefront reflecting surface (7) is constructed as a non-rotational symmetric aspherical structure. The surface profile of the non-rotationally symmetric aspherical structure is described by the following formula: ； in, , For the equation of the reflecting surface in and Major and minor axis coefficients in the direction, for , The curvature of the surface. The constant of the quadratic surface in the equation of the reflecting surface is... , , These are the coefficients of even-order terms of order 4, 6, and 8, respectively. The specific curved surface profile of the aspherical structure is optimized and matched based on the actual equiphase surface shape when the emitted beam of the high-power semiconductor FP laser (4) propagates to the location of the reflective surface. The purpose is to ensure that the beam that reaches the reflective surface from the high-power semiconductor FP laser (4) can be accurately reflected back into the high-power semiconductor FP laser (4) with the greatest efficiency, thereby effectively coupling into and forming the second FP resonant cavity (15). , , , , , , The value is obtained by fitting the isophase point data of the emitted beam of the high-power semiconductor FP laser (4) at a predetermined position; The first elastic deformation mechanism (6) is connected to the Gaussian beam reconstruction wavefront reflecting surface (7) and is used to drive the Gaussian beam reconstruction wavefront reflecting surface (7) to move under the action of external force, thereby changing the cavity length of the second FP resonant cavity (15). The base (5) is used to fix the high-power semiconductor FP laser (4) and is connected to the first elastic deformation mechanism (6).

2. The integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor laser according to claim 1, characterized in that, The sensing chip also includes a stage (9), and the high-power semiconductor FP laser (4) is disposed on the upper surface of the stage (9). A thin film circuit (8) is disposed on the upper surface of the stage (9). The thin film circuit (8) is connected to an external power supply (11) and is used to inject current into the high-power semiconductor FP laser (4), that is, to light up the high-power semiconductor FP laser (4).

3. The integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor laser according to claim 2, characterized in that, The electrodes of the high-power semiconductor FP laser (4) are connected to the thin-film circuit (8) via gold wire bonding (10). The light-emitting end face of the high-power semiconductor FP laser (4) is connected to the coupling fiber (2) via photonic wire bonding waveguide (3) for low-loss output light coupling and input into the spectrometer (1) for spectral analysis. A base (5) is provided on the upper surface of the high-power semiconductor FP laser (4). The base (5) is connected to one end of the first elastic deformation mechanism (6). The other end of the first elastic deformation mechanism (6) is connected to the Gaussian beam reconstruction wavefront reflecting surface (7). The first elastic deformation mechanism (6) causes the position of the Gaussian beam reconstruction wavefront reflecting surface (7) to shift along the transmission direction of the output light of the high-power semiconductor FP laser (4).

4. The integrated micro-force and micro-displacement sensing chip based on TPP and semiconductor laser according to claim 1, characterized in that, The output lasing wavelength of the high-power semiconductor FP laser (4) Simultaneously modulated by the first FP resonant cavity (13) and the second FP resonant cavity (15); when external force When the Gaussian beam reconstruction wavefront reflecting surface (7) is acted upon, the first elastic deformation mechanism (6) drives the Gaussian beam reconstruction wavefront reflecting surface (7) to displace. This causes the cavity length of the second FP resonant cavity (15) to be reduced from the initial cavity length. Become The change in the cavity length of the second FP resonant cavity (15) results in a change in the output lasing wavelength of the high-power semiconductor FP laser (4). Measurable wavelength shift occurs. The external force With the displacement The relationship between them is: ,in The stiffness coefficient of the first elastic deformation mechanism (6); the measurable wavelength drift With the displacement There is a corresponding relationship between them, which can be achieved by measuring the wavelength drift. Determine the displacement and the external force .

5. A method for fabricating an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser, applicable to the chip described in any one of claims 1-4, characterized in that, include: S1. Provide a high-power semiconductor FP laser (4), the high-power semiconductor FP laser (4) having two opposing natural cleavage surfaces, one of which is a second natural cleavage surface (14) designated as a first laser end face for forming an external cavity, and the other of which is a first natural cleavage surface (12) designated as a second laser end face for light output; S2. Using a two-photon polymerization process, a base (5), a first elastic deformation mechanism (6), and a Gaussian beam reconstruction wavefront reflector (7) are integrally manufactured on or relative to the high-power semiconductor FP laser (4), such that the base (5) is fixed to the high-power semiconductor FP laser (4), the first elastic deformation mechanism (6) connects the base (5) and the Gaussian beam reconstruction wavefront reflector (7), and the Gaussian beam reconstruction wavefront reflector (7) and the first laser end face of the high-power semiconductor FP laser (4) together constitute the second FP resonant cavity (15). S3. A photonic wire bonding waveguide (3) is fabricated using a two-photon polymerization process to optically couple the second laser end face of the high-power semiconductor FP laser (4) to the coupling fiber (2).

6. The method for fabricating an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser according to claim 5, characterized in that, The high-power semiconductor FP laser (4) in step S1 is constructed from bottom to top by stacking a substrate, a buffer layer, a planar coupled waveguide layer, a lower confinement layer, a multiple quantum well layer, an upper confinement layer, an etch barrier layer, a waveguide layer, and a contact layer. S11. A buffer layer, a planar coupled waveguide layer and a lower confinement layer are sequentially grown on the substrate by metal-organic compound vapor deposition. Then, a multi-quantum well layer is grown on the lower confinement layer, an upper confinement layer is grown on the multi-quantum well layer, and then an etching barrier layer is grown above the upper confinement layer. S12. Deposit InP above the corrosion barrier layer, and then grow the corrosion barrier layer, waveguide layer and contact layer in sequence. S13. The waveguide layer and contact layer are etched to form ridges, and electrical isolation is etched to achieve partitioning. A front metal electrode is grown in the ridge region above the contact layer. S14. Thinning and polishing the back side of the substrate, evaporating the back electrode and heating to obtain an alloy, and then cleaving the chip to obtain a high-power semiconductor quantum well FP laser.

7. The method for fabricating an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser according to claim 5, characterized in that, The steps in step S2, which involve manufacturing the base (5), the first elastic deformation mechanism (6), and the Gaussian beam reconstructed wavefront reflecting surface (7) using a two-photon polymerization process, include: S21. Fix the high-power semiconductor FP laser (4) to the processing stage, and apply photosensitive resin to the upper surface of the high-power semiconductor FP laser (4) and the predetermined processing area near the end face of the first laser. S22. Using optical imaging and image recognition algorithms, the predetermined printing position on the high-power semiconductor FP laser (4) is accurately identified, and based on the preset three-dimensional digital model of the base (5), the first elastic deformation mechanism (6) and the Gaussian beam reconstructing the wavefront reflecting surface (7), the laser beam is aligned and a focused laser beam is used to selectively induce a polymerization reaction in the photosensitive resin through the two-photon absorption effect, and a three-dimensional structure is constructed by scanning and exposing point by point, line by line, and layer by layer. S23. After exposure, the unpolymerized photosensitive resin is removed by development and then cleaned to expose and obtain the base (5), the first elastic deformation mechanism (6) and the Gaussian beam reconstruction wavefront reflector (7) integrated with the high-power semiconductor FP laser (4).

8. The method for fabricating an integrated micro-force and micro-displacement sensing chip based on TPP and a semiconductor laser according to claim 5, characterized in that, The step S3, which involves fabricating the photonic wire-bonded waveguide (3) using a two-photon polymerization process, includes: S31. Align the second laser end face of the high-power semiconductor FP laser (4) with the input end of the coupling fiber (2) and fix them on a common substrate. Then apply photosensitive resin to a predetermined processing area between the second laser end face and the input end of the coupling fiber (2). S32. Using a high-power objective lens observation system and combined with an image recognition algorithm, identify the optical port position and normal direction of the second laser end face and the input end of the coupling fiber (2), and plan the required three-dimensional path and geometry of the photonic wire bonding waveguide (3) accordingly. S33. According to the planned path and geometry, a focused laser beam is used to selectively initiate a polymerization reaction inside the photosensitive resin through the two-photon absorption effect, thereby completing the exposure forming of the photonic wire bonded waveguide (3). S34. After exposure, the unpolymerized photosensitive resin is removed by a development process to expose and obtain the photonic wire bonding waveguide (3) that connects the second laser end face of the high-power semiconductor FP laser (4) to the input end of the coupling optical fiber (2).

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