A single-mode tapered waveguide spectrum detection device and a detection method thereof

Abstract

The embodiment of the present application discloses a kind of single-mode tapered waveguide spectrum detection device and its detection method;The embodiment of the present application includes input waveguide, it is configured to support single-mode propagation in target working wavelength range, for receiving light to be measured and make it transmit in single-mode form;Tapered waveguide, its input end is coupled with the output end of input waveguide, tapered waveguide has gradually changing cross-sectional dimension along the direction of light propagation, and different wavelengths of light produce distinguishable leakage light in different axial positions when propagating in it;Detector array is distributed along at least one side of tapered waveguide, for detecting the leakage light intensity of tapered waveguide at different axial positions;Wherein, device is configured to output the spectral information of light to be measured based on the mapping relationship between preset wavelength and axial position according to leakage light intensity.It can realize high spectral resolution and high spectral contrast while maintaining wide spectral range by the embodiment of the present application.

Description

Technical Field

[0001] This application relates to the field of spectral detection technology, specifically to a spectral detection device and detection method based on a single-mode tapered waveguide. Background Technology

[0002] Spectrometers play an irreplaceable role in astronomical observation, biochemical analysis, and materials characterization. In recent years, with the increasing demand for portable and field testing, miniaturized spectrometers have attracted widespread attention due to their advantages such as small size, light weight, and low power consumption, and have been applied in scenarios such as agriculture, marine, and environmental monitoring. However, most current miniaturized spectrometers still use traditional dispersive or filtering architectures, achieving compactness only by reducing the size of optical components. In essence, they have not broken through the original design paradigm, often at the expense of key performance characteristics such as spectral resolution, spectral contrast, or spectral continuity.

[0003] For example, miniature spectrometers based on gratings or prisms are limited by short optical paths, making it difficult to achieve high resolution (e.g., tens of thousands or more) and high spectral contrast (>30dB); while solutions using filter arrays or multi-channel detectors face problems such as poor spectral continuity and large crosstalk between channels; although interferometric or computational spectral methods can reduce size, they usually rely on complex algorithms, multiple measurements or precise scanning mechanisms, making it difficult to meet the requirements of real-time, static, and highly robust detection. Summary of the Invention

[0004] This application provides a single-mode tapered waveguide-based spectral detection device and method. By utilizing the correspondence between the leakage position and wavelength in the tapered waveguide, static spectral reconstruction without gratings and mechanical scanning can be achieved, which can maintain a wide spectral range while achieving high spectral resolution and high spectral contrast.

[0005] This application provides a single-mode tapered waveguide-based spectral detection device, the device comprising:

[0006] The input waveguide, configured to support single-mode propagation within the target operating wavelength range, is used to receive the light under test and transmit it in single-mode form.

[0007] A tapered waveguide, whose input end is coupled to the output end of the input waveguide, has a gradually changing cross-sectional dimension along the direction of light propagation. When light of different wavelengths propagates within it, it produces distinguishable leakage light at different axial positions.

[0008] A detector array, distributed along at least one side of a tapered waveguide, is used to detect the intensity of leaked light at different axial positions of the tapered waveguide;

[0009] The device is configured to output the spectral information of the light to be measured based on the intensity of the leaked light, according to a preset mapping relationship between wavelength and axial position.

[0010] In some embodiments, a signal processing unit is further included, which is connected to the detector array and is used to store the mapping relationship between wavelength and axial position, and to convert the leakage light intensity at each axial position into the spectral intensity value of the corresponding wavelength according to the mapping relationship.

[0011] In some embodiments, the input waveguide and the tapered waveguide are made of the same material and integrated on the same substrate.

[0012] In some embodiments, the cross-sectional width of the tapered waveguide decreases monotonically, increases monotonically, or gradually changes according to a preset contour along the direction of light propagation.

[0013] In some embodiments, the detector array is spatially aligned with the leakage light radiation region of the tapered waveguide to receive and detect leakage light distributed along the axial direction of the tapered waveguide.

[0014] In some embodiments, the input waveguide and the tapered waveguide are made of an optically transparent dielectric material, which includes, but is not limited to, silicon nitride, amorphous silicon, or polymers.

[0015] In some embodiments, the detector array is a photodetector array, including at least one of a CMOS image sensor, a CCD linear array, a PIN photodiode array, or a single-photon avalanche diode array.

[0016] This application also provides a single-mode tapered waveguide-based spectral detection method, applied to a spectral detection device including an input waveguide, a tapered waveguide, and a detector array. The input waveguide is coupled to the tapered waveguide, which has a gradually changing cross-sectional dimension along the light propagation direction, causing different wavelengths of light to generate resolvable leakage light at different axial positions when propagating within it. The detector array is distributed along at least one side of the tapered waveguide. The method includes:

[0017] Receive the light under test transmitted in single-mode form from the input waveguide to the tapered waveguide;

[0018] The intensity of leakage light at each axial position of the tapered waveguide is detected by a detector array;

[0019] Based on the preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength, which is used as the spectral intensity value of each wavelength.

[0020] Based on the spectral intensity values ​​of each wavelength, the spectral information of the light to be measured is constructed and output.

[0021] In some embodiments, detecting the leakage light intensity at various axial positions of the tapered waveguide using a detector array includes:

[0022] The raw electrical signals output by each detection unit in the detector array are acquired, and the raw electrical signals correspond to the leakage light intensity detected by each detection unit.

[0023] Dark current subtraction and pixel response non-uniformity correction are performed on the original electrical signal to obtain the corrected leakage light intensity.

[0024] In some embodiments, based on a preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength as the spectral intensity value for each wavelength, including:

[0025] Based on the pre-stored mapping relationship between wavelength and axial position, and the axial position corresponding to each detection unit in the detector array, determine the wavelength corresponding to each axial position;

[0026] The intensity of the leaked light at the axial position is taken as the spectral intensity value of the corresponding wavelength.

[0027] This application also provides an electronic device, including a processor and a memory, wherein the memory stores multiple instructions; the processor loads instructions from the memory to execute the steps in any of the single-mode tapered waveguide spectral detection methods provided in this application.

[0028] This application also provides a computer-readable storage medium storing multiple instructions adapted for loading by a processor to execute steps in any of the single-mode tapered waveguide spectral detection methods provided in this application.

[0029] This application also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps in any of the single-mode tapered waveguide spectral detection methods provided in this application.

[0030] In this application, the input waveguide is coupled to a tapered waveguide, and the tapered waveguide has a gradually changing cross-sectional dimension along the light propagation direction. This allows light of different wavelengths to generate resolvable leakage light at different axial positions due to the wavelength dependence of the effective refractive index and radiation phase when propagating within it. The detector array is distributed along at least one side of the tapered waveguide. Thus, the light under test is transmitted to the tapered waveguide in single-mode form via the input waveguide, effectively suppressing multimode interference and ensuring that the leakage position is determined only by the wavelength and the waveguide geometry. Subsequently, the leakage light intensity at each axial position of the tapered waveguide is detected by the detector array to obtain a light intensity distribution that corresponds one-to-one with the spatial position, thereby providing a physical basis for wavelength resolution. Furthermore, according to the preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength as the spectral intensity value of that wavelength, thereby realizing a direct conversion from spatial domain signal to wavelength domain spectrum. Finally, the spectral information of the light under test is constructed and output based on the spectral intensity values ​​of each wavelength, thereby completing the static reconstruction of the entire spectrum. Therefore, this application does not rely on dispersive elements such as gratings or mechanical scanning mechanisms, and can achieve high-fidelity spectral detection with only a single exposure, while maintaining a wide spectral range and achieving high spectral resolution and high spectral contrast. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1a This is a schematic diagram of the structure of the single-mode tapered waveguide spectral detection device provided in the embodiments of this application;

[0033] Figure 1b This is a schematic diagram of the intensity distribution of leaked light along the axial direction of a tapered waveguide at different wavelengths, provided in an embodiment of this application.

[0034] Figure 1c These are the intensity distribution curves of the leaked light at different wavelengths along the axial position of the tapered waveguide provided in the embodiments of this application;

[0035] Figure 1d This is a spectral resolution diagram provided in an embodiment of this application;

[0036] Figure 2 This is a schematic flowchart of the single-mode tapered waveguide spectral detection method provided in the embodiments of this application;

[0037] Figure 3 This is a schematic diagram of the structure of the single-mode tapered waveguide spectral detection system provided in the embodiments of this application;

[0038] Among them, Figure 1a In the diagram, S1 is the input waveguide, S2 is the tapered waveguide, and S3 is the detection unit in the detector array. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] This application provides a single-mode tapered waveguide spectral detection device and its detection method.

[0041] The single-mode tapered waveguide-based spectral detection method is mounted on a single-mode tapered waveguide-based spectral detection system, which can be integrated into an electronic device, such as a terminal or server. The terminal can be a mobile phone, tablet, smart Bluetooth device, laptop, or personal computer (PC); the server can be a single server or a server cluster consisting of multiple servers.

[0042] In some embodiments, the single-mode tapered waveguide-based spectral detection system can also be integrated into multiple electronic devices. For example, the single-mode tapered waveguide-based spectral detection system can be integrated into multiple servers, and the single-mode tapered waveguide-based spectral detection method of this application can be implemented by multiple servers.

[0043] In some embodiments, the server may also be implemented as a terminal.

[0044] The following sections provide detailed descriptions of each example. It should be noted that the sequence numbers of the following embodiments are not intended to limit the preferred order of the embodiments.

[0045] In this embodiment, a single-mode tapered waveguide spectral detection device is provided, such as... Figure 1a The device is as follows:

[0046] The input waveguide, configured to support single-mode propagation within the target operating wavelength range, is used to receive the light under test and transmit it in single-mode form.

[0047] A tapered waveguide, whose input end is coupled to the output end of the input waveguide, has a gradually changing cross-sectional dimension along the direction of light propagation. When light of different wavelengths propagates within it, it produces distinguishable leakage light at different axial positions.

[0048] A detector array, distributed along at least one side of a tapered waveguide, is used to detect the intensity of leaked light at different axial positions of the tapered waveguide;

[0049] The device is configured to output the spectral information of the light to be measured based on the intensity of the leaked light, according to a preset mapping relationship between wavelength and axial position.

[0050] The input waveguide S1 refers to the optical waveguide structure used to receive external light under test and guide it into the tapered waveguide in single-mode form. Its geometry (such as width and thickness) and materials are designed to support only the fundamental mode (TE0 or TM0) propagation within the target operating wavelength range, suppressing the excitation of higher-order modes.

[0051] The target operating wavelength range refers to the incident light wavelength range covered by this spectroscopic detection device, for example, 0.9 μm to 1.7 μm. Within this band, the input waveguide maintains single-mode transmission characteristics, and the tapered waveguide can produce a resolvable wavelength-position mapping.

[0052] Single-mode refers to the propagation of light in a waveguide as a single spatial mode (usually the fundamental mode), without the participation of higher-order modes. In this application, "single-mode" specifically refers to the input waveguide supporting and supporting only one guided mode for all wavelengths within the target operating wavelength range, thereby ensuring a stable spatial distribution of the input optical field and eliminating mode crosstalk.

[0053] A tapered waveguide S2 refers to a waveguide structure where one end is coupled to the input waveguide, and the cross-sectional dimensions change continuously (e.g., the width decreases monotonically) along the direction of light propagation. Its function is to utilize the geometric dispersion effect to ensure that single-mode light of different wavelengths satisfies radiation conditions at different axial positions during propagation, thereby generating spatially resolvable leakage light.

[0054] Coupled connection refers to the efficient transfer of optical power between the output end of the input waveguide and the input end of the tapered waveguide through a low-loss method (such as direct end-face docking, thermal tape transition, etc.), ensuring a smooth transition of the single-mode field from the input waveguide to the tapered waveguide without introducing mode mismatch or significant reflection.

[0055] The direction of light propagation refers to the main axis of light transmission from the input waveguide through the tapered waveguide, usually defined as the z-axis direction, along which the tapered waveguide's gradient structure unfolds.

[0056] The cross-sectional dimension refers to the geometric dimensions of a waveguide in a plane perpendicular to the direction of light propagation, typically including width (x-direction) and thickness (y-direction). In this application, the gradual change in cross-sectional dimension is mainly manifested in the continuous change of width along the propagation direction.

[0057] Axial position refers to the spatial coordinate position along the direction of light propagation (z direction). Due to the different radiation phases or cutoff conditions in the tapered waveguide, light of different wavelengths will have maximum leakage at their respective specific axial positions, forming a one-to-one correspondence between wavelength and position.

[0058] Leakage light refers to single-mode light propagating in a tapered waveguide where the total internal reflection condition is no longer met locally due to the gradual change in the waveguide's cross-section, causing some of its energy to escape from the waveguide as a radiation mode. The spatial distribution of this leakage light is wavelength dependent.

[0059] It is understood that the "distinguishable leakage light" mentioned in this paper refers to a sufficiently large spatial separation between the main peak positions z_max(λ1) and z_max(λ2) of the leakage light intensity distribution excited in the tapered waveguide along the waveguide axis (z direction) for any two different wavelength components λ1 and λ2 with a preset minimum wavelength interval Δλ (e.g., Δλ = 0.1 nm) in the input spectrum. This allows the detection unit located near these positions to detect signal intensities significantly higher than the background noise or crosstalk levels of adjacent wavelengths. In other words, "distinguishable" means that the leakage light corresponding to different wavelengths has a spatially distinguishable intensity peak distribution, and its crosstalk is lower than a preset threshold (e.g., -30 dB), thereby allowing the back-end processing unit to accurately invert the spectral composition of the original incident light based on the preset mapping relationship between wavelength and axial position.

[0060] A detector array refers to an array (such as a CMOS linear array, PIN diode array, etc.) composed of multiple photodetector units S3 arranged along at least one side of a tapered waveguide, used to spatially resolve the reception and detection of leakage light intensity at different axial positions.

[0061] Leakage light intensity refers to the leakage light power or photocurrent signal received by each detection unit in the detector array at a specific axial position, reflecting the magnitude of the radiated energy at that position.

[0062] The preset mapping relationship between wavelength and axial position refers to the functional relationship established in advance through calibration experiments or electromagnetic simulation. Alternatively, a lookup table can be used to determine the axial position measured by the detector array. Uniquely corresponds to wavelength This mapping relationship is determined by the geometric parameters of the tapered waveguide and the material dispersion characteristics.

[0063] Spectral information refers to the intensity distribution of the light under test in the wavelength domain, that is, a set of discrete or continuous information. Data pairs, among which wavelength The corresponding spectral intensity value. This device reconstructs this information by assigning the leakage light intensity to the corresponding wavelength according to a mapping relationship.

[0064] like Figure 1a As shown, in use, the light under test is incident on the input waveguide through a coupling system consisting of an optical fiber and a lens. The input waveguide is configured to support single-mode propagation within the target operating wavelength range, stabilizing the incident light into single-mode light after transmission. Subsequently, this single-mode light enters a tapered waveguide coupled to its output end and propagates in a structure with a gradually changing cross-sectional size along the light propagation direction, resulting in distinguishable leakage light at their respective axial positions for different wavelengths of light.

[0065] An array of detectors distributed along at least one side of the conical waveguide receives the leaked light and converts the optical signals received by each detector unit into electrical signals, thereby obtaining the leakage light intensity data distributed along the axial direction of the conical waveguide. This intensity data constitutes a spatially resolved light intensity distribution (which can be regarded as a one-dimensional "light intensity pattern").

[0066] Furthermore, based on the preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to the corresponding wavelength as the spectral intensity value, and finally the spectral information of the light to be measured is constructed and output.

[0067] It is understandable that the detector array functions by assigning an axial position to each pixel (or detector unit). The output signal is proportional to the leakage light power at that location. The "light intensity pattern" is essentially a set of discrete ( , )data.

[0068] In a specific embodiment, the input waveguide has a cross-sectional dimension of 1 μm × 1 μm and a length of 200 μm. Its geometry is designed to support single-mode propagation within the target operating wavelength range (e.g., 0.9–1.7 μm). Within this wavelength range, light of all incident wavelengths, after being coupled into the input waveguide, can propagate stably in a single mode, thereby ensuring the purity and spatial consistency of the optical field mode output to the tapered waveguide. This characteristic helps maintain the repeatability of leakage behavior and the accuracy of position resolution during subsequent wavelength resolution processes, thus ensuring the accuracy and stability of spectral reconstruction.

[0069] like Figure 1b As shown, the intensity distribution of the leakage light generated by the tapered waveguide along the axial position varies significantly under incident light of different wavelengths, indicating that each wavelength can be spatially distinguished.

[0070] like Figure 1c As shown, the leakage light intensity distribution curves corresponding to different wavelengths are separated from each other and have low crosstalk, demonstrating good wavelength selectivity, which helps to improve the spectral resolution of the device.

[0071] like Figure 1dAs shown, the single-mode tapered waveguide spectral detection device provided in this application embodiment can effectively distinguish similar wavelengths based on the leakage light intensity distribution, and achieve the expected spectral resolution function.

[0072] In a preferred embodiment, such as Figure 1c and 1d As shown, the peak positions of the leakage light generated by the two beams with wavelengths of 1549.8nm and 1550.2nm are clearly separated, and the energy crosstalk between them is extremely low, which meets the requirement of "distinguishable".

[0073] In some embodiments, the input waveguide and the tapered waveguide are fabricated using a plasma-enhanced chemical vapor deposition (PECVD) process.

[0074] In some embodiments, a signal processing unit is further included, which is connected to the detector array and is used to store the mapping relationship between wavelength and axial position, and to convert the leakage light intensity at each axial position into the spectral intensity value of the corresponding wavelength according to the mapping relationship.

[0075] The signal processing unit, an electronic processing module electrically connected to the detector array, is configured to perform spectral reconstruction. Specifically, it includes: storing a preset mapping relationship between wavelengths and axial positions (e.g., in the form of a lookup table or function); receiving leakage light intensity signals at each axial position output by the detector array; assigning the intensity value corresponding to each axial position to its associated wavelength according to the mapping relationship, thereby generating the spectral intensity value for that wavelength; and finally, integrating the spectral intensity values ​​of all wavelengths to construct and output the complete spectral information of the light under test.

[0076] The signal processing unit can be implemented by a microcontroller, field-programmable gate array (FPGA), application-specific integrated circuit (ASIC), or general-purpose processor, and can be integrated into the detection chip or used as an external processing module.

[0077] Spectral intensity value refers to the relative or absolute optical power (or light intensity) of the light under test at a specific wavelength, and is expressed as the radiant energy level corresponding to that wavelength. In this application, the spectral intensity value is obtained by assigning the leakage light intensity measured by the detector array at a certain axial position to the corresponding wavelength according to a preset mapping relationship between wavelength and axial position; the spectral intensity values ​​corresponding to multiple wavelengths together constitute the complete spectral information of the light under test, which is used to characterize its spectral distribution characteristics within the target operating wavelength range.

[0078] Understandably, the introduction of the signal processing unit enables the device to directly reconstruct the intensity distribution in the spatial domain to the spectral information in the wavelength domain under a single static measurement, without relying on iterative algorithms or external calibration processes. At the same time, by accurately matching the correspondence between the leakage location and the wavelength, it effectively suppresses crosstalk between channels, improves spectral contrast and resolution, and thus achieves high-fidelity, real-time, and low-power on-chip spectral detection.

[0079] In some embodiments, the input waveguide and the tapered waveguide are made of the same material and integrated on the same substrate.

[0080] Understandably, this design facilitates the integration of low-loss, high-alignment-precision on-chip optical paths, avoiding reflection, scattering, or mode mismatch caused by differences in materials or interfaces. At the same time, the use of monolithic integration technology can significantly improve the mechanical and thermal stability of the device, reduce packaging complexity and manufacturing costs, and provide fundamental support for the realization of highly reliable, miniaturized, and mass-produced spectral detection chips.

[0081] In a specific embodiment, both the input waveguide and the tapered waveguide are made of silicon nitride (Si3N4). In addition to silicon nitride, other dielectric materials with high optical transparency in the target operating wavelength range can also be selected. For example, silicon (Si) can be used as the waveguide material in the near-infrared band (e.g., 1.2–1.7 μm).

[0082] In some embodiments, the cross-sectional dimensions (thickness and width) of the input end of the tapered waveguide are the same as those of the input waveguide.

[0083] In some embodiments, the cross-sectional width of the tapered waveguide monotonically decreases, monotonically increases, or gradually changes according to a preset profile along the direction of light propagation. This allows for precise control over the variation of the effective refractive index and radiation phase of the guided mode with propagation distance, thereby establishing a one-to-one and distinguishable mapping relationship between wavelength and leakage location.

[0084] Among them, monotonically decreasing refers to the continuous decrease in the cross-sectional width of the tapered waveguide along the direction of light propagation (i.e. from the input end to the output end), the width at any downstream position is no greater than the width at its upstream position, and there is no local increase or plateau region.

[0085] Monotonically increasing refers to the continuous increase in the cross-sectional width of the tapered waveguide along the direction of light propagation, where the width at any downstream position is no less than the width at its upstream position, and there is no local decrease or plateau region.

[0086] Preset profile gradient refers to the continuous variation of the cross-sectional width of the tapered waveguide along the direction of light propagation according to a pre-designed functional relationship (such as linear, exponential, parabolic, or piecewise function) to achieve specific wavelength-position mapping characteristics; this profile can be obtained through electromagnetic simulation or reverse design optimization.

[0087] Understandably, by flexibly designing the tapered waveguide's cross-section gradient, the spectral response characteristics can be adjusted as needed without increasing system complexity, taking into account wide spectral coverage, high resolution, and high signal-to-noise ratio, thus providing an effective technical path for the customized design of miniature spectrometers.

[0088] In some embodiments, the detector array is spatially aligned with the leakage light radiation region of the tapered waveguide to receive and detect leakage light distributed along the axial direction of the tapered waveguide.

[0089] The leakage light radiation region refers to the physical region in a tapered waveguide where, due to the gradual change in cross-sectional dimensions along the direction of light propagation, the guided mode no longer satisfies the total internal reflection condition at a specific axial position, thus coupling some light energy out of the waveguide in the form of radiation modes. This region is distributed along the axial direction of the tapered waveguide, and its position is wavelength-dependent—different wavelengths of light correspond to different main radiation positions, forming a spatially resolvable leakage light distribution.

[0090] In practical implementation, precise spatial alignment between the detector array and the leakage light radiation region of the tapered waveguide maximizes the capture efficiency of the leakage light, effectively avoiding light energy loss due to positional misalignment, thereby improving the system's signal-to-noise ratio. Simultaneously, this alignment ensures that each detection unit accurately corresponds to its target axial position, enabling the reliable application of the preset wavelength-position mapping relationship and guaranteeing the accuracy of spectral reconstruction. Furthermore, precise spatial matching significantly suppresses signal crosstalk and background noise between adjacent wavelengths, contributing to a spectral contrast exceeding 30 dB and fully leveraging the theoretical resolution potential determined by dz / dλ under limited detector pixel size. Therefore, this spatial alignment design is a key technological foundation for achieving high-sensitivity, high-resolution, and high-contrast static spectral detection, significantly enhancing the overall performance and practical value of the miniature spectrometer.

[0091] In some embodiments, the input waveguide and the tapered waveguide are made of an optically transparent dielectric material, which includes, but is not limited to, silicon nitride, amorphous silicon, or polymers.

[0092] In some embodiments, the input waveguide material is a transparent material or a low-absorption material in the operating band. The input waveguide material is selected as silicon nitride in this application, but is not limited to silicon, silicon dioxide, lithium niobate, group III-V semiconductor compounds or polymer materials.

[0093] In some embodiments, the tapered waveguide material may be silicon nitride, but is not limited to silicon, silicon dioxide, lithium niobate, group III-V semiconductor compounds, or polymer materials.

[0094] In some embodiments, the detector array is a photodetector array, including at least one of a CMOS image sensor, a CCD linear array, a PIN photodiode array, or a single-photon avalanche diode array.

[0095] Among them, the CMOS image sensor refers to a photodetector array manufactured based on complementary metal-oxide-semiconductor (CMOS) technology, which can convert incident light signals into electrical signals and integrate readout circuits to support high frame rate and low power consumption two-dimensional or one-dimensional light intensity distribution detection. In this application, it can be configured as a one-dimensional photosensitive area arranged along the axis of the tapered waveguide to receive and quantify the intensity of leaked light.

[0096] A CCD linear array is a one-dimensional photodetector array composed of charge-coupled devices (CCDs). It achieves high-sensitivity, low-noise light intensity acquisition by transferring charge row by row. It is suitable for measuring the axial intensity distribution of leaked light that requires high dynamic range and high uniformity.

[0097] A PIN photodiode array is a detector array composed of multiple photodiodes with PIN structures arranged in one dimension. It has a fast response speed, good linearity, and low dark current, making it suitable for real-time and stable intensity detection of leakage light distributed along the axial direction of a tapered waveguide.

[0098] A single-photon avalanche diode array refers to a high-sensitivity detector array composed of multiple avalanche diodes operating in Geiger mode, capable of detecting weak light signals at the single-photon level; in this application, it can be used for leakage light position resolution and intensity statistics under extremely low optical power conditions.

[0099] In some embodiments, the photodetector is a point detector to acquire spectral information at different axial positions on the tapered waveguide, but it is not limited to a point detector; line detectors and two-dimensional detectors are also possible.

[0100] In summary, this application provides a spectral detection device based on a single-mode tapered waveguide, comprising an input waveguide, a tapered waveguide, and a detector array. This device utilizes the fact that when light of different wavelengths propagates in the tapered waveguide, the gradual change in the waveguide's cross-section generates distinguishable leakage light at different axial positions. The detector array detects the leakage light intensity at each axial position, and spectral reconstruction is achieved by combining this with a preset wavelength-position mapping relationship.

[0101] Compared to traditional commercial spectrometers, this application eliminates the need for gratings, prisms, or mechanical scanning components. It features a highly integrated structure, compact size, and low power consumption, significantly reducing system complexity and manufacturing costs. Furthermore, relying on single-mode transmission and spatial resolution detection, it can achieve high spectral resolution and high contrast under static, single-measurement conditions, effectively balancing portability and high performance, making it suitable for both field and embedded spectral detection scenarios.

[0102] In this embodiment, a single-mode tapered waveguide-based spectral detection method is provided, applied to a spectral detection device including an input waveguide, a tapered waveguide, and a detector array. The input waveguide is coupled to the tapered waveguide, which has a gradually changing cross-sectional dimension along the light propagation direction, causing different wavelengths of light to generate resolvable leakage light at different axial positions when propagating within it. The detector array is distributed along at least one side of the tapered waveguide, such as... Figure 2 The specific process of this single-mode tapered waveguide spectral detection method can be shown as follows:

[0103] 201. Receive the light under test transmitted in single-mode form to the tapered waveguide via the input waveguide.

[0104] 202. The intensity of leakage light at each axial position of the tapered waveguide is detected by a detector array.

[0105] 203. Based on the preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength, which is used as the spectral intensity value of each wavelength.

[0106] 204. Based on the spectral intensity values ​​of each wavelength, construct and output the spectral information of the light to be measured.

[0107] In some embodiments, by performing dark current subtraction and pixel response non-uniformity correction on the raw electrical signal output by the detector array, systematic errors introduced by thermal noise, manufacturing process deviations, and environmental factors are effectively eliminated, thereby significantly improving the accuracy and consistency of leakage light intensity measurement. This signal correction mechanism ensures that the light intensity distribution at different axial positions can truly reflect the wavelength components of the incident light, avoiding spectral distortion, spurious peaks, or baseline fluctuations caused by background drift or differences in pixel sensitivity. This, in turn, guarantees the reliable application of the wavelength-position mapping relationship and improves the fidelity of spectral reconstruction.

[0108] The intensity of leakage light at various axial positions of the tapered waveguide is detected using a detector array, including:

[0109] The raw electrical signals output by each detection unit in the detector array are acquired, and the raw electrical signals correspond to the leakage light intensity detected by each detection unit.

[0110] Dark current subtraction and pixel response non-uniformity correction are performed on the original electrical signal to obtain the corrected leakage light intensity.

[0111] Among them, the original electrical signal refers to the unprocessed electrical signal (such as voltage, current or digital count value) directly output by each detection unit in the detector array after receiving the leaked light. Its amplitude is affected by the incident light intensity, dark current, pixel gain difference and environmental noise.

[0112] Leakage light intensity refers to the optical power density radiated by a tapered waveguide at a specific axial position. Theoretically, it is proportional to the intensity of the corresponding wavelength component in the incident light and is indirectly characterized by the photoelectric response of the detection unit.

[0113] The corrected leakage light intensity refers to the signal that more accurately reflects the true leakage light intensity after dark current subtraction and pixel response non-uniformity correction of the original electrical signal, and is used for subsequent spectral reconstruction.

[0114] Understandably, the process involves first reading the raw electrical signals output by each detection unit in the detector array. These signals include the effective light response, dark current (the background current in the absence of light), and the difference in response between pixels due to manufacturing processes. Then, under conditions of no incident light (or through light-shielding measurement), the dark current signal of each pixel is pre-acquired as a darkframe. During actual measurement, the dark current value of the corresponding pixel is subtracted from the raw electrical signal to eliminate the influence of thermal noise and background drift. Finally, the detector array is uniformly illuminated by a standard light source to obtain the response gain factor (i.e., the response non-uniformity map) of each pixel. The raw electrical signal is divided (or multiplied by a normalization coefficient) by the gain factor of the corresponding pixel to compensate for the inconsistency in sensitivity caused by differences in quantum efficiency, amplification circuits, etc.

[0115] In some embodiments, this mapping assignment mechanism is the core bridge connecting the physical leakage phenomenon and the final spectral output, enabling this application to simultaneously achieve wide spectral coverage, high resolution, high contrast and real-time performance in a compact structure without gratings or moving parts, providing a reliable technical path for miniaturized high-performance spectrometers.

[0116] Based on the preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength, serving as the spectral intensity value for each wavelength, including:

[0117] Based on the pre-stored mapping relationship between wavelength and axial position, and the axial position corresponding to each detection unit in the detector array, determine the wavelength corresponding to each axial position;

[0118] The intensity of the leaked light at the axial position is taken as the spectral intensity value of the corresponding wavelength.

[0119] To better implement the above methods, this application also provides a single-mode tapered waveguide-based spectral detection system. This system can be integrated into an electronic device, such as a terminal or server. The terminal can be a mobile phone, tablet, smart Bluetooth device, laptop, or personal computer; the server can be a single server or a server cluster consisting of multiple servers.

[0120] For example, in this embodiment, the method of this application embodiment will be described in detail by taking a single-mode tapered waveguide spectral detection system specifically integrated into an electronic device as an example.

[0121] For example, such as Figure 3 As shown, this single-mode tapered waveguide-based spectral detection system is applied to a spectral detection device including an input waveguide, a tapered waveguide, and a detector array. The input waveguide is coupled to the tapered waveguide, which has a gradually changing cross-sectional dimension along the light propagation direction, allowing light of different wavelengths to generate resolvable leakage light at different axial positions when propagating within it. The detector array is distributed along at least one side of the tapered waveguide. The device specifically includes a receiving unit 301, a detection unit 302, a mapping unit 303, and a construction unit 304, as follows:

[0122] (a) Receiving unit 301.

[0123] The receiving unit 301 is used to receive the light under test transmitted to the tapered waveguide in single-mode via the input waveguide.

[0124] (ii) Detection unit 302.

[0125] The detection unit 302 is used to detect the intensity of leakage light at each axial position of the tapered waveguide through a detector array.

[0126] In some embodiments, detecting the leakage light intensity at various axial positions of the tapered waveguide using a detector array includes:

[0127] The raw electrical signals output by each detection unit in the detector array are acquired, and the raw electrical signals correspond to the leakage light intensity detected by each detection unit.

[0128] Dark current subtraction and pixel response non-uniformity correction are performed on the original electrical signal to obtain the corrected leakage light intensity.

[0129] (III) Mapping Unit 303.

[0130] The mapping unit 303 is used to assign the leakage light intensity at each axial position to the corresponding wavelength according to the preset mapping relationship between wavelength and axial position, so as to serve as the spectral intensity value of each wavelength.

[0131] (iv) Building Unit 304.

[0132] The construction unit 304 is used to construct and output the spectral information of the light to be measured based on the spectral intensity values ​​of each wavelength.

[0133] In some embodiments, based on a preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength as the spectral intensity value for each wavelength, including:

[0134] Based on the pre-stored mapping relationship between wavelength and axial position, and the axial position corresponding to each detection unit in the detector array, determine the wavelength corresponding to each axial position;

[0135] The intensity of the leaked light at the axial position is taken as the spectral intensity value of the corresponding wavelength.

[0136] In practice, each of the above units can be implemented as an independent entity or can be arbitrarily combined to be implemented as the same or several entities. For the specific implementation of each of the above units, please refer to the previous method embodiments, which will not be repeated here.

[0137] Therefore, the embodiments of this application can utilize the correspondence between the leakage position and the wavelength in the graded waveguide to achieve static spectral reconstruction without gratings and mechanical scanning, and can achieve high spectral resolution and high spectral contrast while maintaining a wide spectral range.

[0138] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be performed by instructions, or by instructions controlling related hardware. These instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.

[0139] Therefore, embodiments of this application provide a computer-readable storage medium storing a plurality of instructions that can be loaded by a processor to execute the steps in any of the single-mode tapered waveguide spectral detection methods provided in embodiments of this application.

[0140] The storage medium may include: read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0141] Since the instructions stored in the storage medium can execute the steps in any of the trash rack cleaning path planning methods provided in the embodiments of this application, the beneficial effects that any of the single-mode conical waveguide spectral detection methods provided in the embodiments of this application can achieve can be realized. For details, please refer to the previous embodiments, which will not be repeated here.

[0142] According to one aspect of this application, a computer program product or computer program is provided, comprising computer program / instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer program / instructions from the computer-readable storage medium and executes the computer program / instructions, causing the electronic device to perform the method provided in the above embodiments based on single-mode tapered waveguide spectral detection.

[0143] The above provides a detailed description of a single-mode tapered waveguide spectral detection method and apparatus provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and its core ideas. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A single-mode tapered waveguide-based spectral detection device, characterized in that, The device includes: The input waveguide, configured to support single-mode propagation within the target operating wavelength range, is used to receive the light under test and transmit it in single-mode form. A tapered waveguide, the input end of which is coupled to the output end of the input waveguide, the tapered waveguide having a gradually changing cross-sectional dimension along the light propagation direction, and different wavelengths of light propagating within it generate distinguishable leakage light at different axial positions; A detector array, distributed along at least one side of the tapered waveguide, is used to detect the intensity of leaked light at different axial positions of the tapered waveguide; The device is configured to output the spectral information of the light under test based on the intensity of the leaked light, according to a preset mapping relationship between wavelength and axial position.

2. The apparatus as claimed in claim 1, characterized in that, It also includes a signal processing unit connected to the detector array, which is used to store the mapping relationship between the wavelength and the axial position, and convert the leakage light intensity at each axial position into the spectral intensity value of the corresponding wavelength according to the mapping relationship.

3. The apparatus as described in claim 1, characterized in that, The input waveguide and the tapered waveguide are made of the same material and integrated on the same substrate.

4. The apparatus as claimed in claim 1, characterized in that, The cross-sectional width of the tapered waveguide decreases monotonically, increases monotonically, or gradually changes according to a preset contour along the direction of light propagation.

5. The apparatus as claimed in claim 1, characterized in that, The detector array is spatially aligned with the leakage light radiation region of the tapered waveguide to receive and detect leakage light distributed along the axial direction of the tapered waveguide.

6. The apparatus as claimed in claim 1, characterized in that, The input waveguide and the tapered waveguide are made of an optically transparent dielectric material, which includes, but is not limited to, silicon nitride, amorphous silicon, or polymers.

7. The apparatus as claimed in claim 1, characterized in that, The detector array is a photodetector array, including at least one of a CMOS image sensor, a CCD linear array, a PIN photodiode array, or a single-photon avalanche diode array.

8. A method for spectral detection based on a single-mode tapered waveguide, characterized in that, A spectral detection device comprising an input waveguide, a tapered waveguide, and a detector array, wherein the input waveguide is coupled to the tapered waveguide, the tapered waveguide having a gradually changing cross-sectional dimension along the light propagation direction such that light of different wavelengths propagating within it produces resolvable leakage light at different axial positions, and the detector array is distributed along at least one side of the tapered waveguide, the method comprising: Receive the light under test transmitted in single-mode form to the tapered waveguide via the input waveguide; The intensity of leakage light at each axial position of the tapered waveguide is detected by the detector array. Based on the preset mapping relationship between wavelength and axial position, the leakage light intensity at each axial position is assigned to its corresponding wavelength, which is used as the spectral intensity value of each wavelength. Based on the spectral intensity values ​​of each wavelength, the spectral information of the light to be measured is constructed and output.

9. The method as described in claim 8, characterized in that, The step of detecting the leakage light intensity at each axial position of the tapered waveguide using the detector array includes: The original electrical signals output by each detection unit in the detector array are obtained, and the original electrical signals correspond to the leakage light intensity detected by each detection unit. The original electrical signal is subjected to dark current subtraction and pixel response non-uniformity correction to obtain the corrected leakage light intensity.

10. The method as described in claim 8, characterized in that, The step of assigning the leakage light intensity at each axial position to its corresponding wavelength based on a preset mapping relationship between wavelength and axial position, as the spectral intensity value of each wavelength, includes: Based on the pre-stored mapping relationship between wavelength and axial position, and the axial position corresponding to each detection unit in the detector array, the wavelength corresponding to each axial position is determined; The intensity of the leaked light at the axial position is taken as the spectral intensity value of the corresponding wavelength.

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