A microring resonance-enhanced on-chip Raman spectrometer

Abstract

This invention discloses a microring resonant-enhanced on-chip integrated Raman spectrometer, monolithically integrated on a thin-film lithium niobate or thin-film lithium tantalate electro-optic integrated photonic platform. It includes a microring resonant Raman enhancement structure based on a subwavelength grating waveguide, an on-chip spectral resolution unit, and a photodetector. The microring resonant Raman enhancement structure performs the interaction between the Raman excitation light and the sample under test and collects the Raman scattering signal. The on-chip spectral resolution unit is connected to the microring resonant Raman enhancement structure via an on-chip optical waveguide to perform spectral analysis on the enhanced Raman scattering signal. The photodetector is located at the output of the on-chip spectral resolution unit to detect the spectrally analyzed light signal. The advantages of this invention compared to existing technologies are: it provides a microring resonant-enhanced on-chip integrated Raman spectrometer that achieves efficient Raman signal enhancement, on-chip coupled transmission, and spectral analysis, solving the miniaturization and integration challenges of traditional Raman spectral sensing systems.

Description

Technical Field

[0001] This invention relates to the field of integrated optoelectronics and Raman spectroscopy sensing, specifically to a microring resonance-enhanced on-chip integrated Raman spectrometer. Background Technology

[0002] With the continuous advancement of technology, trace detection has become particularly important in fields such as biological detection, environmental monitoring, and safety control. Raman spectroscopy sensing technology, with its "molecular fingerprint" characteristic capability of single-molecule sensitivity, has been widely used in related fields such as disease prevention and drug screening.

[0003] However, traditional Raman spectroscopy sensing technology has obvious bottlenecks: on the one hand, the Raman scattering intensity is extremely weak, and its traditional enhancement technology relies on the design of the enhancement substrate, resulting in poor signal repeatability; on the other hand, signal acquisition and analysis rely on independent and bulky spectrometer equipment, which is difficult to meet the needs of rapid on-site detection and real-time monitoring.

[0004] In recent years, integrated photonic devices based on subwavelength grating waveguide structures have provided new solutions for Raman substrate design. Compared with traditional continuous dielectric waveguides, subwavelength grating waveguide structures allow for on-demand engineering design of refractive index through precise control of structural parameters such as period and duty cycle. Most importantly, their unique physical structure allows the sample to enter through the grating gaps or surface, enabling sufficient interaction between the analyte molecules and the excitation light, significantly improving the excitation efficiency of the Raman scattering signal. Furthermore, subwavelength grating waveguide structures can be directly integrated into the waveguide optical path, laying the structural foundation for achieving high-sensitivity and high-stability on-chip Raman spectroscopy sensing.

[0005] Furthermore, the miniaturization and low cost of on-chip spectrometers can solve the problems of large size and high cost of traditional Raman spectrometers. Currently, there are four main technical approaches for on-chip spectrometers: miniaturized dispersive optical systems, narrowband filter systems, Fourier transform spectrometers, and reconstruction spectrometers. However, most on-chip spectrometers currently only function as spectral analysis instruments and have not yet achieved integrated design for "spectral analysis" from "signal excitation and enhancement to collection and detection," especially the design and implementation of high-performance on-chip integrated systems.

[0006] Therefore, designing and implementing a sensing system that integrates a Raman enhancement structure based on a subwavelength grating waveguide and an on-chip spectrometer is of great value for the development of portable, high-sensitivity trace detection technology. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned technical defects and provide a micro-ring resonance-enhanced on-chip integrated Raman spectrometer that realizes efficient Raman signal enhancement, on-chip coupled transmission and spectral analysis, and solves the miniaturization and integration problems of traditional Raman spectroscopy sensing systems.

[0008] To solve the above-mentioned technical problems, the technical solution provided by the present invention is: a microring resonance enhanced on-chip integrated Raman spectrometer, which is monolithically integrated on a thin-film lithium niobate or thin-film lithium tantalate electro-optic integrated photonic platform;

[0009] This includes a micro-ring resonant Raman enhancement structure based on a subwavelength grating waveguide structure, an on-chip spectral resolution unit, and a photodetector;

[0010] The microring resonant Raman enhancement structure performs the interaction between Raman excitation light and the sample under test and collects Raman scattering signals.

[0011] The on-chip spectral resolution unit is connected to the micro-ring resonant Raman enhancement structure through an on-chip optical waveguide to perform spectral analysis on the enhanced Raman scattering signal;

[0012] The photodetector is located at the output of the on-chip spectral resolution unit to detect the optical signal after spectral analysis.

[0013] Preferably, the microring resonant Raman enhancement structure includes an input waveguide, a first optical coupler, a microring resonant cavity, a second optical coupler, and an output waveguide;

[0014] The micro-ring resonant cavity is a subwavelength grating waveguide structure with a period less than half the operating wavelength.

[0015] Preferably, the subwavelength grating waveguide structure comprises a periodically arranged array of high refractive index etched grooves or dielectric pillars, the periodic pores of which form sample channels that can be filled by gas or liquid samples.

[0016] When the Raman excitation light satisfies the resonance condition, the light field is transmitted multiple times within the micro-ring, enhancing the Raman scattering signal of the sample placed in the pore. The enhanced Raman signal is then directly coupled to the on-chip spectral resolution unit at the back end through the output waveguide.

[0017] Preferably, the subwavelength grating waveguide structure comprises a periodically arranged array of high refractive index etched grooves or dielectric pillars, the periodic pores of which form sample channels that can be filled by gas or liquid samples.

[0018] When the Raman excitation light satisfies the resonance condition, the light field is transmitted multiple times within the micro-ring, enhancing the Raman scattering signal of the sample placed in the pore. The enhanced Raman signal is then directly coupled to the on-chip spectral resolution unit at the back end through the output waveguide.

[0019] Preferably, the on-chip spectral resolution unit is a computational reconstruction spectrometer based on cascaded microrings, including a coupled straight waveguide, k microring filters with different radii, and electro-optic modulation electrodes corresponding to each microring filter, where k ≥ 2.

[0020] Preferably, the electro-optic phase modulation electrodes are distributed on both sides of an interferometric arm waveguide, and the effective refractive index of the arm waveguide is modulated based on the electro-optic effect of thin-film lithium niobate or thin-film lithium tantalate to introduce an optical path difference.

[0021] Preferably, the electro-optic modulation electrode independently tunes the resonant wavelength of each micro-ring filter to change the spectral response, and reconstructs the Raman spectrum using compressed sensing or regularized reconstruction algorithms.

[0022] Preferably, the Raman excitation light is a continuous wave or pulsed laser with a wavelength in the visible to near-infrared band, which enters the microring resonant Raman enhancement structure through end-face coupling, grating coupling or prism coupling.

[0023] Preferably, the photodetector is a single silicon-based photodetector, integrated on an electro-optical integrated photonics platform based on heterogeneous integration technology.

[0024] Another aspect of the present invention discloses a Raman spectroscopy detection method for a microring resonance-enhanced on-chip integrated Raman spectrometer, comprising the following steps:

[0025] S1: The Raman excitation light is coupled into the micro-ring resonant Raman enhancement structure, and the wavelength of the excitation light is matched to the resonant wavelength of the micro-ring resonant cavity through electro-optic tuning;

[0026] S2: The interaction between the sample under test and the enhanced light field generates a Raman scattering signal;

[0027] S3: The enhanced Raman scattering signal is transmitted to the on-chip spectral resolution unit for spectral analysis via an on-chip optical waveguide;

[0028] S4: The photodetector detects the light signal after spectral analysis, reconstructs the Raman scattering signal, and completes the Raman spectrum detection.

[0029] The advantages of this invention compared to the prior art are:

[0030] By integrating the Raman enhancement structure and the spectrometer onto the same chip, the traditional separate Raman substrate and external large spectrometer structure are eliminated, greatly reducing the system size and realizing the miniaturization and portability of the Raman spectroscopy sensing system.

[0031] The system is based on a thin-film lithium niobate or thin-film lithium tantalate electro-optic integrated photonics platform, and achieves rapid measurement of Raman signals through electro-optic tuning and spectral reconstruction. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of a microring resonance-enhanced on-chip integrated Raman spectrometer system.

[0033] Figure 2 A schematic diagram of a thin-film lithium niobate or thin-film lithium tantalate electro-optic integrated photonics platform;

[0034] Figure 3 This is a schematic diagram of a microring resonant Raman enhancement unit based on a subwavelength grating waveguide structure;

[0035] Figure 4 This is a schematic diagram of a cascaded microring on-chip computational reconstruction spectrometer.

[0036] Figure 5 This is a schematic diagram of the structure of a Mach-Zehnder interferometric Fourier transform spectrometer.

[0037] Figure 6 This is a schematic diagram of an enhanced Raman spectrometer when using a Mach-Zehnder interferometric Fourier transform spectrometer;

[0038] Figure 7 This is a schematic diagram of an enhanced Raman spectrometer using a cascaded microring on-chip computational reconstruction spectrometer.

[0039] In the figure: 1. Micro-ring resonator based on subwavelength grating waveguide structure; 2, 4, 6. Electro-optic modulation electrodes; 3. Micro-ring filter; 5. Beam splitter or beam combiner. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings.

[0041] Combined with appendix Figure 1-7 As shown, a microring resonant enhanced on-chip spectrometer includes a microring resonant Raman enhancement structure based on a subwavelength grating waveguide structure, an on-chip spectral resolution unit for spectral analysis, and a photodetector.

[0042] The microring resonant Raman enhancement structure based on the subwavelength grating waveguide provides a near-field interaction region for the target analyte, enabling efficient interaction between the Raman excitation light and the sample and collection of Raman scattering signals to output the enhanced Raman scattering signal; the on-chip spectrometer is connected to the microring resonant Raman enhancement structure via an on-chip optical waveguide.

[0043] The photodetector is located at the output of the spectral resolution unit and optically coupled to it. Raman excitation light is coupled into the micro-ring resonant Raman enhancement structure, interacts with the sample to be tested, and transmits the excited Raman signal to the spectral resolution unit for spectral analysis. The photodetector then detects the signal and achieves rapid measurement through electro-optic tuning, thereby realizing monolithic integration of Raman signal enhancement, spectral analysis, and signal detection.

[0044] The microring resonant Raman enhancement structure includes an input waveguide, a first optical coupler, a microring resonant cavity, a second optical coupler, and an output waveguide.

[0045] The micro-ring resonant cavity is a subwavelength grating waveguide structure, which is composed of a periodically arranged array of high refractive index etched grooves or dielectric pillars. Its period is less than half of the working wavelength. While forming an equivalent refractive index waveguide, the periodic apertures of this structure provide a channel for the sample under test to enter the light field inside the resonant cavity.

[0046] When the Raman excitation light meets the resonance condition, it enters the microring resonant cavity through the input waveguide coupling. The light field is transmitted multiple times in the microring, which greatly enhances the Raman scattering signal of the sample placed in the pore.

[0047] The enhanced Raman signal is directly coupled to the on-chip spectral resolution unit at the back end through the output waveguide, which effectively reduces the coupling loss between modules and improves the system transmission efficiency and detection performance. The thin-film lithium niobate or thin-film lithium tantalate electro-optic integrated photonic platform has good electro-optic effect and chemical stability. It can not only achieve precise locking of the excitation wavelength and rapid scanning of the spectrum through electro-optic tuning, but also maintain stable performance in complex biochemical detection environments.

[0048] When the spectral resolution unit of the on-chip spectrometer adopts a Fourier transform spectrometer based on a Mach-Zehnder interferometer (MZI) structure, it includes: a beam splitter and a beam combiner composed of a multimode coupler (MMI) or a directional coupler, and two interferometer arms connected between the beam splitter and the beam combiner. At least one interferometer arm is provided with an electro-optic phase modulation electrode to achieve scanning or discrete sampling of the optical path difference. The electro-optic phase modulation electrode is distributed on both sides of the waveguide of one interferometer arm to apply a scanning voltage. The effective refractive index of the waveguide of the arm is modulated based on the electro-optic effect of thin-film lithium niobate to introduce different optical path differences. Furthermore, the light to be measured is split after being input from the beam splitter composed of the MMI or the directional coupler. The two beams enter the upper arm and the lower arm of the MZI for transmission, respectively. After electro-optic modulation, one interferometer arm generates an optical path difference with the other arm. The two beams are output through the beam combiner composed of the MMI or the directional coupler to achieve interference and beam combining of the two arms of the MZI. Finally, the spectrum to be measured is reconstructed by Fourier transform to obtain Raman spectral information.

[0049] When the spectral resolution unit of the on-chip spectrometer adopts a computational reconstruction spectrometer based on cascaded microrings, it includes: a coupled straight waveguide, k microring filters, and k pairs of electro-optic modulation electrodes corresponding to the k microring filters. Here, k ≥ 2, and the radii of each microring filter are different, thus their free spectral ranges are also different. The computational reconstruction spectrometer based on cascaded microrings also includes electro-optic modulation electrodes integrated on the waveguide layer, which scan the resonant wavelength of the microrings through the electro-optic effect to achieve a set of spectral response matrices. After multiple modulations, the signal light generates different projection signals, and the intensity sequence is collected by the detector. Combined with the pre-calibrated response matrix, the Raman spectrum is reconstructed through compressed sensing or a regularized reconstruction algorithm. The Raman excitation light is a continuous wave or pulsed laser with a wavelength in the visible to near-infrared band, which enters the input waveguide through end-face coupling, grating coupling, or prism coupling.

[0050] The photodetector is a single photodetector, which is integrated onto the electro-optic integrated photonic platform through heterogeneous integration processes (including but not limited to bonding, micro-transfer printing, and flip-chip bonding); multi-channel detection is achieved through electro-optic scanning of the on-chip spectrometer.

[0051] In specific implementations of this invention, the contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0052] This embodiment provides a sensing system for a microring resonance-enhanced on-chip integrated Raman spectrometer. The entire system is implemented using a monolithic thin-film lithium niobate or thin-film lithium tantalate electro-optic integrated photonic platform. The optical path of the entire system sequentially passes through… Figure 1 The structure includes a Raman enhancement structure based on a subwavelength grating waveguide, an on-chip spectral resolution unit, and a photodetector. The on-chip spectral resolution unit can be either a Mach-Zehnder interferometric Fourier transform spectrometer or a cascaded micro-ring computational reconstruction on-chip spectrometer. Both structures are described in this embodiment.

[0053] Example 1: Integrated Sensing System Using a Fourier Transform Spectrometer Based on MZI Structure

[0054] The micro-ring resonant Raman enhancement structure based on a subwavelength grating waveguide is connected to the Mach-Zehnder interferometer on-chip spectral resolution unit via an on-chip optical waveguide. The Raman-enhanced scattering signal generated by the subwavelength grating waveguide structure is coupled into a straight waveguide and then transmitted to the Mach-Zehnder interferometer on-chip Fourier transform spectrometer. Its complete structure is shown below. Figure 6 As shown.

[0055] Preferably, the waveguide of the microring resonant cavity is a subwavelength grating waveguide structure, and the periodically arranged etched grooves or dielectric pillars form sample channels that can be filled by gas or liquid samples. When the incident Raman excitation light wavelength is precisely matched to a certain resonant wavelength of the microring resonant cavity through electro-optic tuning, the light field resonates within the closed microring and is significantly enhanced. At this time, the sample under test located within the microring resonant cavity or in the near-field interaction region will interact with this enhanced light field, greatly enhancing the Raman scattering signal.

[0056] Furthermore, the periodic pores of the subwavelength grating waveguide structure can precisely confine liquid or gaseous samples in the light field enhancement region through capillary adsorption and surface confinement, thereby further improving the detection sensitivity. The enhanced Raman scattered light is coupled into the straight waveguide through the micro-ring and transmitted to the spectral resolution unit of the Fourier transform spectrometer based on the MZI structure for spectral demodulation and analysis.

[0057] like Figure 5 As shown, a Fourier transform spectrometer based on an MZI structure includes: a beam splitter and a beam combiner composed of an MMI or a directional coupler, and two interference arms connected between the beam splitter and the beam combiner. At least one interference arm is provided with an electro-optic phase modulation electrode to achieve scanning or discrete sampling of the optical path difference.

[0058] Furthermore, electro-optic phase modulation electrodes are distributed on both sides of an interferometer arm waveguide to apply a scanning voltage. In this embodiment, the waveguide core material is thin-film lithium niobate, which has an electro-optic effect. An applied electric field can change the refractive index of lithium niobate, thereby changing the effective refractive index of the waveguide. The light to be measured is split after being input from a beam splitter composed of an MMI or a directional coupler. The two beams are transmitted through the upper and lower arms of the MZI, respectively. After photoelectric modulation, one interferometer arm generates an optical path difference with the other arm. The optical path difference (OPD) between the upper and lower arms of the MZI is expressed as OPD = Δn. eff ·L, where Δn eff The change in effective refractive index is represented by the applied electric field V, and L represents the length of the modulation region on a single arm of the MZI.

[0059] Based on the fundamental relationship between optical path difference and phase difference, Δφ = 2πOPD / λ, where λ represents the wavelength of light in vacuum, when the optical path difference causes the phase difference between the two arms to reach π, the corresponding applied voltage is the half-wave voltage. Combining this with the expression for optical path difference, the half-wave voltage V under this single-arm drive structure is derived. π The expression for (λ) is V π (λ)=λ / (2·Δn eff (V π )·L), Δn eff (V π This represents the change in effective refractive index of the modulation arm when the applied voltage equals the half-wave voltage. It combines the optical path difference and the half-wave voltage V.π The expression for the phase difference between the output beams of the upper and lower arms of the MZI (λ) can be simplified to Δφ = π·V / V π (λ).

[0060] In this embodiment, the two beams are combined by interference from the output of a beam combiner composed of an MMI or a directional coupler to achieve the beam combining of the two arms of the MZI. The beam combiner is connected to a photodetector, and the photocurrent signal I(V) detected by the detector changes with the applied voltage V. Finally, the detector signal is reconstructed by Fourier transform to obtain the Raman spectral information. A schematic diagram of the waveguide cross-section of the MZI is shown below. Figure 2 As shown.

[0061] Example 2: Integrated Sensing System Using a Cascaded Micro-Ring Computational Reconstruction On-Chip Spectrometer

[0062] The difference between this embodiment and Embodiment 1 is that the on-chip spectral resolution unit adopts a computational reconstruction on-chip spectrometer with cascaded microrings. The rest of the structure is exactly the same as that of Embodiment 1, and its complete structural diagram is shown below. Figure 7 As shown.

[0063] This embodiment is based on compressed sensing theory. Raman spectral signals are sparse signals. According to compressed sensing theory, they can be reconstructed without distortion by sampling at frequencies far below the Nyquist frequency. The core of this process is to achieve high-precision reconstruction of the Raman spectrum by using dynamic sampling through cascaded micro-ring filters and solving underdetermined matrices.

[0064] The resonant wavelength of the microring filter can be tuned by electro-optic modulation electrodes. The response of the cascaded microring filter can be regarded as an independent sampling channel, enabling multiple dynamic sampling of the Raman spectrum under different voltages. Specifically, let the Raman spectrum signal to be reconstructed be... Where N is the number of wavelength sampling points, i.e., the spectral dimension; through M dynamic samplings at different voltages, the output light intensity signal of the photodetector is obtained as follows: , where each element in y corresponds to the output light intensity of the photodetector in one sampling.

[0065] According to compressed sensing theory, the entire sampling process can be described as follows: ,in This is called the sampling matrix, which can be obtained in advance through calibration measurements. The physical meaning is the response coefficient at the Nth wavelength point corresponding to the Mth sampling; This represents sampling channel noise. Considering the sparsity of Raman spectroscopy, the spectral reconstruction problem can be transformed into a constrained optimization problem, solved by minimizing the sparsity regularization term. The core formula is: .in It is the L1 norm of signal x. Let ε be the residual norm between the sampled signal and the reconstructed signal, and ε be the residual threshold. This optimization problem can be solved using mature coefficient reconstruction algorithms such as the Iterative Soft Thresholding Algorithm (IST) and the Alternating Directional Multiplier Method (ADMM) to obtain the optimal estimate x of the Raman spectrum to be reconstructed, thus completing the computational reconstruction of the Raman spectrum.

[0066] like Figure 4 As shown, the cascaded microring computational reconstruction on-chip spectrometer specifically includes: a coupled straight waveguide, k microring filters, and k pairs of electro-optic modulation electrodes corresponding to each microring filter, where k ≥ 2, and the radii of the k microring filters are all different.

[0067] Furthermore, the coupled straight waveguide is connected to the Raman enhancement structure based on the subwavelength grating waveguide structure. Its core function is to efficiently couple the enhanced Raman scattering signal to the cascaded micro-ring filter, providing a low-loss signal source for subsequent sampling and reconstruction.

[0068] Preferably, k micro-ring filters are arranged in an array along the coupled straight waveguide and are laterally coupled to the coupled straight waveguide; wherein the coupling gap can be flexibly set according to the target coupling coefficient required for actual construction, and its parameters will affect the sampling matrix, which will not be specifically limited in this application.

[0069] Furthermore, the radii of each micro-ring filter are different, ensuring that each micro-ring has a different free spectral range, thereby reducing the correlation of the sampling matrix and increasing the measurement bandwidth.

[0070] Furthermore, by adjusting the voltage of each pair of electro-optic modulation electrodes, the effective refractive index of the corresponding microring waveguide can be changed by utilizing the electro-optic effect of lithium niobate or lithium tantalate, introducing different additional phases. The resonant wavelength of the microring filter can be independently tuned, enabling fine scanning of the spectral detection range and high-resolution spectral reconstruction.

[0071] Before measurement, the cascaded micro-ring computational reconstruction on-chip spectrometer needs to be calibrated to obtain the sampling matrix. During operation, the Raman signal, enhanced by the subwavelength grating waveguide structure, enters the coupled straight waveguide, then passes through a cascaded micro-ring filter, and the total light intensity is measured by a photodetector. By scanning the electro-optic modulation electrodes, the resonant wavelengths of each micro-ring can be successively tuned, and the corresponding output light intensity is recorded using a photodetector. By combining this with the compressed sensing reconstruction method, the complete Raman spectrum can be reconstructed.

[0072] Preferably, the photodetectors described in the two embodiments are fabricated from silicon (Si) material, enabling light detection from the visible to near-infrared range, and meeting the requirements for light intensity detection sensitivity and response speed during Raman spectroscopy sampling. This silicon-based photodetector is integrated onto a thin-film lithium niobate or thin-film lithium tantalate photonic platform using bonding, micro-transfer, or flip-chip heterogeneous integration processes.

[0073] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0074] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A micro-ring resonator enhanced on-chip integrated Raman spectrometer, characterized in that: Monolithically integrated on a thin-film lithium niobate or thin-film lithium tantalate electro-optical integrated photonics platform; This includes a micro-ring resonant Raman enhancement structure based on a subwavelength grating waveguide structure, an on-chip spectral resolution unit, and a photodetector; The microring resonant Raman enhancement structure performs the interaction between Raman excitation light and the sample under test and collects Raman scattering signals. The on-chip spectral resolution unit is connected to the micro-ring resonant Raman enhancement structure through an on-chip optical waveguide to perform spectral analysis on the enhanced Raman scattering signal; The photodetector is located at the output of the on-chip spectral resolution unit to detect the optical signal after spectral analysis.

2. The micro-ring resonator enhanced on-chip integrated Raman spectrometer according to claim 1, wherein: The microring resonant Raman enhancement structure includes an input waveguide, a first optical coupler, a microring resonant cavity, a second optical coupler, and an output waveguide. The micro-ring resonant cavity is a subwavelength grating waveguide structure with a period less than half the operating wavelength.

3. The micro-ring resonator enhanced on-chip integrated Raman spectrometer according to claim 2, wherein: The subwavelength grating waveguide structure comprises a periodically arranged array of high refractive index etched grooves or dielectric pillars, and its periodic pores form sample channels that can be filled by gas or liquid samples. When the Raman excitation light satisfies the resonance condition, the light field is transmitted multiple times within the micro-ring, enhancing the Raman scattering signal of the sample placed in the pore. The enhanced Raman signal is then directly coupled to the on-chip spectral resolution unit at the back end through the output waveguide.

4. The micro-ring resonator enhanced on-chip integrated Raman spectrometer according to claim 1, wherein: The on-chip spectral resolution unit is a Fourier transform spectrometer based on a Mach-Zehnder interferometer structure, including a beam splitter and a beam combiner composed of a multimode coupler or a directional coupler, two interferometer arms connected between the beam splitter and the beam combiner, and an electro-optic phase modulation electrode disposed on at least one interferometer arm.

5. The micro-ring resonator enhanced on-chip integrated Raman spectrometer according to claim 1, wherein: The on-chip spectral resolution unit is a computational reconstruction spectrometer based on cascaded microrings, including a coupled straight waveguide, k microring filters with different radii, and electro-optic modulation electrodes corresponding to each microring filter, where k ≥ 2.

6. The micro-ring resonator enhanced on-chip integrated Raman spectrometer of claim 4, wherein: The electro-optic phase modulation electrodes are distributed on both sides of an interferometric arm waveguide, and the effective refractive index of the arm waveguide is modulated based on the electro-optic effect of thin-film lithium niobate or thin-film lithium tantalate to introduce an optical path difference.

7. The micro-ring resonator enhanced on-chip integrated Raman spectrometer of claim 5, wherein: The electro-optic modulation electrode independently tunes the resonant wavelength of each micro-ring filter to change the spectral response, and reconstructs the Raman spectrum through compressed sensing or regularized reconstruction algorithms.

8. The micro-ring resonator enhanced on-chip integrated Raman spectrometer of claim 1, wherein: The Raman excitation light is a continuous wave or pulsed laser with a wavelength in the visible to near-infrared band, which enters the microring resonant Raman enhancement structure through end-face coupling, grating coupling or prism coupling.

9. The micro-ring resonator enhanced on-chip integrated Raman spectrometer of claim 1, wherein: The photodetector is a single silicon-based photodetector, integrated on an electro-optical integrated photonics platform based on heterogeneous integration technology.

10. A Raman spectroscopy detection method based on a microring resonance-enhanced on-chip integrated Raman spectrometer according to any one of claims 1-9, characterized in that: Includes the following steps: S1: The Raman excitation light is coupled into the micro-ring resonant Raman enhancement structure, and the wavelength of the excitation light is matched to the resonant wavelength of the micro-ring resonant cavity through electro-optic tuning; S2: The interaction between the sample under test and the enhanced light field generates a Raman scattering signal; S3: The enhanced Raman scattering signal is transmitted to the on-chip spectral resolution unit for spectral analysis via an on-chip optical waveguide; S4: The photodetector detects the light signal after spectral analysis, reconstructs the Raman scattering signal, and completes the Raman spectrum detection.

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