Signal detection method and device, electronic equipment and medium

Abstract

The invention provides a signal detection method and device, electronic equipment and a medium, and the method comprises the steps: receiving incident light from a deep ultraviolet light source; converting the incident light from a deep ultraviolet band by using a wavelength conversion crystal to obtain a visible band optical signal; enabling the visible wave band optical signal to pass through a narrow-band optical filter and a photosensitive diode in sequence so as to convert the optical signal into a current signal; in an electromagnetic shielding environment, processing the current signal to obtain a digital signal; and performing signal processing including digital filtering and signal averaging on the digital signal, and inverting and outputting intensity information of the deep ultraviolet light source based on the processed data. According to the invention, the light intensity detection efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of signal detection technology, and more specifically, to a signal detection method, apparatus, electronic device, and medium. Background Technology

[0002] In cutting-edge technology fields such as biomedical imaging, environmental monitoring, semiconductor industry, and national defense security, the accurate detection of extremely weak light signals, especially those in the deep ultraviolet band, has become a key core technology. For example, biofluorescence imaging requires the detection of weak fluorescence emitted by cells, and environmental monitoring requires the analysis of weak spectra produced by trace chemical substances. These applications all require detection systems with extremely high sensitivity and stability.

[0003] Currently, the detection of weak ultraviolet light mainly relies on ultraviolet-enhanced photomultiplier tubes (UV-Enhanced Photomultiplier Tubes) or special photodiodes, combined with high-gain amplification circuits and basic filtering methods. However, these existing solutions have significant inherent drawbacks: the inherent noise of photomultiplier tubes, such as dark current, is relatively large; the system is susceptible to external electromagnetic interference; and the quantum efficiency in the deep ultraviolet band remains limited. These problems collectively result in the signal-to-noise ratio and stability of existing technologies failing to meet the requirements for precise detection in extremely weak light scenarios. Summary of the Invention

[0004] In view of the above, the purpose of this application is to provide a signal detection method, apparatus, electronic device and medium to overcome at least one of the above-mentioned defects.

[0005] In a first aspect, embodiments of this application provide a signal detection method, the method comprising: receiving incident light from a deep ultraviolet light source; converting the incident light from the deep ultraviolet band using a wavelength conversion crystal to obtain a visible band optical signal; passing the visible band optical signal sequentially through a narrowband filter and a photodiode to convert the optical signal into a current signal; processing the current signal to obtain a digital signal; performing signal processing on the digital signal, including digital filtering and signal averaging, and inverting and outputting the intensity information of the deep ultraviolet light source based on the processed data.

[0006] In one optional embodiment of this application, a visible light signal is obtained by: using a wavelength conversion crystal to receive incident light in the deep ultraviolet band and absorb deep ultraviolet photons, causing electrons of cerium ions in the wavelength conversion crystal to transition from the ground state to the excited state. After a non-radiative process, the electrons transition from the excited state back to the ground state, releasing visible light photons with low energy and wavelengths within a preset wavelength range, thus obtaining a visible light signal.

[0007] In one optional embodiment of this application, the current signal is obtained by passing visible light within a preset wavelength range through a narrow-band filter in sequence to filter out background noise and obtain purified visible light; the purified visible light is incident on a photodiode, and the photodiode generates a current signal proportional to the light intensity.

[0008] In one optional embodiment of this application, the digital signal is obtained by: converting the current signal into a voltage signal through a current-to-voltage conversion circuit; amplifying and level-shifting the voltage signal to adjust it to a preset voltage range; converting the level-shifted single-ended voltage signal into a differential signal; and performing analog-to-digital conversion on the differential signal to obtain the digital signal.

[0009] In one optional embodiment of this application, the intensity information of the deep ultraviolet light source is inverted and output in the following manner: energy integration calculation is performed on the data after digital filtering and signal averaging; based on the result of the energy integration calculation, the intensity information of the deep ultraviolet light source is inverted and output.

[0010] In one optional embodiment of this application, the step of inverting and outputting the intensity information of the deep ultraviolet light source based on the energy integral calculation result includes: multiplying the integral value obtained by the energy integral calculation with a preset calibration coefficient to obtain the intensity value of the inverted deep ultraviolet light; determining whether the intensity value of the deep ultraviolet light exceeds a preset alarm threshold; if it exceeds the alarm threshold, generating and outputting alarm information containing the intensity value; if it does not exceed the threshold, directly outputting the intensity value of the deep ultraviolet light as intensity information.

[0011] Secondly, embodiments of this application also provide a signal detection device, the device comprising: an incident light receiving module for receiving incident light from a deep ultraviolet light source; a visible light signal obtaining module for converting the incident light from the deep ultraviolet band using a wavelength conversion crystal to obtain a visible light signal; a current signal conversion module for sequentially passing the visible light signal through a narrowband filter and a photodiode to convert the light signal into a current signal; a digital signal obtaining module for processing the current signal to obtain a digital signal; and an intensity information output module for performing signal processing on the digital signal, including digital filtering and signal averaging, and inverting and outputting the intensity information of the deep ultraviolet light source based on the processed data.

[0012] In one optional embodiment of this application, the current signal conversion module is further configured to: receive the incident light in the deep ultraviolet band using a wavelength conversion crystal and absorb deep ultraviolet photons, causing the electrons of cerium ions in the wavelength conversion crystal to transition from the ground state to the excited state. After a non-radiative process, the electrons transition from the excited state back to the ground state, releasing visible light photons with low energy and wavelengths within a preset wavelength range, thereby obtaining a visible light signal.

[0013] Thirdly, embodiments of this application also provide an electronic device, including: a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the memory via the bus, and when the machine-readable instructions are executed by the processor, the steps of the method described above are performed.

[0014] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the method described above.

[0015] This application provides a signal detection method, apparatus, electronic device, and medium. The method includes: receiving incident light from a deep ultraviolet light source; converting the incident light from the deep ultraviolet band to a visible band optical signal using a wavelength conversion crystal; sequentially passing the visible band optical signal through a narrowband filter and a photodiode to convert the optical signal into a current signal; processing the current signal in an electromagnetically shielded environment to obtain a digital signal; performing signal processing on the digital signal, including digital filtering and signal averaging; and inverting and outputting the intensity information of the deep ultraviolet light source based on the processed data. This application improves the efficiency of light intensity detection.

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

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart of the signal detection method provided in the embodiments of this application; Figure 2 This is a flowchart of the process for acquiring a current signal provided in an embodiment of this application; Figure 3A flowchart for obtaining digital signals provided in an embodiment of this application; Figure 4 This is a schematic diagram of the signal detection device provided in the embodiments of this application; Figure 5 The present application provides a schematic diagram of the structure of an electronic device. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0020] First, the applicable scenarios for this application will be introduced. This application can be applied to the field of signal detection technology.

[0021] Research has revealed that in cutting-edge scientific fields such as biomedical research, environmental science, high-end manufacturing, and national defense, the accurate detection of extremely weak light signals has become a crucial core technology. For example, in bioluminescence imaging, it is necessary to detect the weak fluorescence emitted by cells or molecular markers to study life activities; in environmental monitoring, it is necessary to accurately analyze the weak spectral signals generated by trace chemicals in the atmosphere or water; in the semiconductor industry, the monitoring of extreme ultraviolet (EUV) production processes and the detection of wafer defects rely on the capture of scattered ultraviolet light; and deep space exploration, lidar (LiDAR), and high-energy physics experiments often face the challenge of extremely low signal strength and huge background noise.

[0022] Traditional photoelectric detection methods often fail to meet accuracy and reliability requirements in these application scenarios with extremely low signal-to-noise ratios due to insufficient sensitivity and poor resistance to electromagnetic interference.

[0023] Currently, common existing technical solutions for detecting weak light signals, especially in the ultraviolet band, mainly include directly using ultraviolet enhancement photomultiplier tubes (PMTs) or specially optimized ultraviolet-sensitive photodiodes, combined with high-gain amplifier circuits and simple filtering methods to try to extract signals. These solutions generally suffer from problems such as large inherent noise (e.g., dark current of PMTs), susceptibility to electromagnetic interference, limited quantum efficiency in the ultraviolet band, and high cost, resulting in poor signal-to-noise ratio and stability in extremely weak light scenarios.

[0024] Based on this, embodiments of this application provide a signal detection method, apparatus, electronic device, and medium to solve the technical problems of insufficient sensitivity, poor anti-interference ability, and low signal-to-noise ratio in the detection of extremely weak light signals in the deep ultraviolet band in the prior art.

[0025] Specifically, this application solves the core problem of low quantum efficiency in the ultraviolet band of traditional silicon-based sensors by introducing a wavelength conversion crystal to efficiently convert deep ultraviolet light into visible light; by constructing a multi-level noise suppression system of "optical filtering-electromagnetic shielding-differential transmission-digital processing", the anti-interference capability of the system is significantly improved; and finally, high sensitivity and high stability detection of deep ultraviolet light sources under extremely weak light intensity conditions are achieved.

[0026] The purpose of this application is to achieve high signal-to-noise ratio and high stability for accurate detection of optical signals from deep ultraviolet (DUV) band or other extremely low intensity light sources. This invention relates to a high-sensitivity, high-anti-interference optical detection device and method suitable for extremely weak light intensity conditions, belonging to the field of high-end optoelectronic detection and precision instrument technology. It is particularly suitable for applications with significant environmental interference, complex background noise, or signal strength approaching the detector's background limit, such as in cutting-edge technologies and industrial fields like biofluorescence imaging, single-photon detection, and semiconductor wafer defect detection.

[0027] The underlying principle is as follows: Ultraviolet light emitted by the DUV light source is incident on the YAG-CE crystal through a small aperture. The YAG-CE crystal undergoes fluorescence conversion into visible light, which is then attenuated by a filter into weak visible light before reaching the photodiode detection unit of the sensor. The photodiode generates a current signal, which is processed by the processing circuit through electromagnetic shielding, I / V conversion, signal amplification, level shifting, and differential conversion. The processing results are then sent to the host computer unit, which processes and analyzes the data to achieve high-sensitivity and high-anti-interference beam energy detection in weak light intensity scenarios.

[0028] Please see Figure 1 , Figure 1 This is a flowchart illustrating the signal detection method provided in an embodiment of this application. Figure 1 As shown in the embodiments of this application, the signal detection method includes: S101, Receives incident light from a deep ultraviolet light source.

[0029] Here, the incident light from the DUV (deep ultraviolet) source is first passed through a tiny aperture with a size on the order of micrometers.

[0030] In the optical path design, incident ultraviolet light from the DUV source first passes through a precisely machined micron-sized aperture. This aperture not only limits the field of view and reduces stray light interference but also significantly improves the system's spatial resolution and signal-to-noise ratio. Subsequently, the ultraviolet light is precisely incident on a YAG-CE (cerium-doped yttrium aluminum garnet) crystal. This crystal, as a highly efficient wavelength conversion material, possesses high quantum efficiency and stable physicochemical properties, enabling it to effectively downconvert incident deep ultraviolet photons to visible light in the 500-600 nm wavelength range, thus achieving wavelength shift. This conversion process is crucial because it overcomes the problems of low quantum efficiency and poor responsivity in the ultraviolet region of conventional silicon-based photoelectric sensors, laying the foundation for subsequent high-sensitivity detection.

[0031] Aperture size (micrometer level): This parameter is a structural parameter achieved through precision machining. Its specific value (e.g., diameter 10μm, 20μm, etc.) is designed and selected based on the balance between the required spatial resolution and light transmission of the system. The aperture acts as a physical baffle, and its size is determined after machining.

[0032] Deep ultraviolet wavelength: refers to ultraviolet light with wavelengths in the range of 200 nanometers to 300 nanometers. This is an input parameter determined by the characteristics of the selected deep ultraviolet light source (such as a DUV laser, deuterium lamp, etc.).

[0033] S102. The incident light is converted from the deep ultraviolet band to the visible band light signal using a wavelength conversion crystal.

[0034] Cerium-doped yttrium aluminum garnet (YAG-CE) crystal is used as the wavelength conversion crystal. This crystal absorbs deep ultraviolet photons and converts high-energy deep ultraviolet photons into low-energy visible light photons through energy level transitions (excitation → relaxation → emission) of cerium ions within it.

[0035] The conversion crystal (YAG-CE) is the core material for achieving downconversion. Its type (yttrium aluminum garnet), doping element (cerium), doping concentration, and geometry are pre-selected during system design based on factors such as conversion efficiency, physical strength, and cost.

[0036] Output visible light wavelength range (500nm to 600nm): This is an inherent parameter determined by the physical properties (emission spectrum) of the YAG-CE crystal itself. When the crystal is excited by deep ultraviolet light, it will spontaneously emit fluorescence within this specific wavelength range.

[0037] Furthermore, visible light signals are obtained in the following ways: By using a wavelength conversion crystal to receive incident light in the deep ultraviolet band and absorb deep ultraviolet photons, the electrons of cerium ions in the wavelength conversion crystal are transitioned from the ground state to the excited state. After a non-radiative process, the electrons transition from the excited state back to the ground state, releasing visible light photons with low energy and wavelengths within a preset wavelength range, thus obtaining a visible light signal.

[0038] Here, a specific material, cerium-doped yttrium aluminum garnet crystal (YAG-CE), is used to achieve a "down-conversion" from deep ultraviolet light to visible light.

[0039] First, deep ultraviolet light is incident and absorbed, which will allow deep ultraviolet incident light with wavelengths in the range of 200-300 nanometers (nm) to be precisely irradiated onto the YAG-CE crystal.

[0040] The incident light wavelength (200-300nm) is the system's input condition, determined by the luminescence characteristics of the selected deep ultraviolet light source (such as a DUV laser or a low-pressure mercury lamp). For example, a mercury lamp with an emission wavelength of 254nm can be selected as the light source.

[0041] Then, cerium ions undergo excitation and energy level transitions. After the YAG-CE crystal absorbs deep ultraviolet photons, the cerium ions (Ce³⁺) in the crystal... + The internal electrons transition from the stable 4f ground state energy level to the higher 5d excited state energy level.

[0042] Here, cerium ions (Ce³) + ( ) are artificially incorporated luminescent centers in YAG crystals, and their existence and concentration are inherent properties set during crystal preparation.

[0043] The ground state and excited state energy levels, the positions of these levels and the energy difference between them are determined by Ce³. + The physical constants determined by the quantum mechanical properties of ions in a YAG crystal field are an integral property of this material.

[0044] Finally, visible light photon emission occurs. The cerium ions in the high-energy excited state are unstable, and their electrons first undergo nonradiative relaxation to a lower energy level of the 5d excited state, and then spontaneously transition from this lower excited state back to the 4f ground state. During this process, excess energy is released in the form of visible light photons.

[0045] The preset wavelength range (500nm to 600nm) is the final output parameter of this step. This range is not arbitrarily set, but is determined by the inherent emission spectrum characteristics of the YAG-CE crystal material itself. When excited by ultraviolet light, it mainly emits yellow-green light with a center wavelength of approximately 550nm, and the spectral range typically covers 500-600nm. This parameter can be obtained and confirmed by consulting the product datasheet of the crystal or by measuring its fluorescence emission spectrum using a spectrometer.

[0046] Through the above steps, a visible light signal with a center wavelength of approximately 550 nm and a spectral range between 500 and 600 nm was obtained. Compared to the original deep ultraviolet light, this signal's wavelength falls within the response range of silicon-based photodiodes, where quantum efficiency is at its highest, thus laying a solid foundation for subsequent high-sensitivity detection.

[0047] S103. The visible light signal is passed through a narrowband filter and a photodiode in sequence to convert the light signal into a current signal.

[0048] The visible light generated in step S102 is passed through a narrow-band filter whose center wavelength of transmission band matches the emission peak of YAG-CE (e.g., 550 nm), and the filtered "purified visible light" is incident on the photosensitive surface of the photodiode.

[0049] Here, the center wavelength and bandwidth of the filter, for example, the center wavelength can be 550nm and the bandwidth can be 10nm. These are optical element parameters specifically selected based on the emission spectrum of the YAG-CE crystal (output of step S102) to ensure maximum transmission of signal light and suppression of background light.

[0050] Regarding photodiode models and performance, models with large photosensitive surfaces, high responsivity, and extremely low dark current are preferred. These are key performance parameters obtained from the photodiode manufacturer's datasheet and are selected during the design process based on the required sensitivity and noise level.

[0051] The current signal is a physical quantity that is proportional to the light intensity and is generated in real time by a photodiode based on its responsivity (A / W) and the received light power.

[0052] The converted visible light signal passes through a narrowband filter system. This filter is optimized for the emission spectrum of the YAG-CE crystal, effectively suppressing ambient background light and interference from other non-target wavelengths, thereby attenuating and purifying the light signal to a weak intensity suitable for detection by the photoelectric sensor. The purified beam is then guided into a high-performance photodiode detection unit.

[0053] Photocurrent signal processing is the core of achieving high sensitivity and high immunity. The entire circuit unit is encapsulated in a professionally designed electromagnetic shield to effectively suppress external radio frequency interference, power frequency noise, and various electromagnetic coupling noises. The generated weak current signal first passes through an I / V conversion circuit composed of a high-precision, low-bias-current operational amplifier, converting the current signal into a voltage signal. This stage design requires special attention to the selection of the feedback resistor and thermal noise management to ensure the linearity of the conversion and low-noise characteristics. The photodiode is preferably a model with a large photosensitive surface, high responsivity, and extremely low dark current to ensure that it can still generate measurable photocurrent under weak light conditions.

[0054] Specifically, please refer to Figure 2 , Figure 2 The flowchart for acquiring the current signal provided in the embodiments of this application is as follows: Figure 2 As shown, the current signal is obtained in the following way: S201. Visible light within a preset wavelength range is sequentially passed through a narrow-band filter to filter out background noise and obtain purified visible light.

[0055] Visible light with wavelengths in the 500-600 nm range emitted from the YAG-CE crystal is incident perpendicularly onto a narrow-band interference filter. This filter is designed to allow only a narrow wavelength range of light to pass through.

[0056] The preset wavelength range (input) can be 500-600nm. This parameter is derived from the inherent emission spectrum of the YAG-CE crystal in the previous step S102 and is the object of processing in this step.

[0057] The optical components are pre-determined and procured based on the emission spectrum (input signal characteristics) of the YAG-CE crystal and the system's anti-interference requirements. The optical properties of the filter (center wavelength, bandwidth, blocking depth, etc.) are determined by its coating design and manufacturing process and are inherent attributes of the component. Selecting a filter that matches the crystal's emission peak aims to maximize signal transmittance while filtering out background noise from ambient light (such as fluorescent lamps and natural light).

[0058] Purified visible light (output): This is the light signal obtained after passing through a filter, with its wavelength components mainly concentrated within the filter's passband (e.g., 545-555nm). Its purity is ensured by the performance of the filter.

[0059] S202. Purified visible light is incident onto a photodiode, which generates a current signal proportional to the light intensity.

[0060] The "purified visible light" output from step S201 is optically guided (e.g., directly aligned or focused through a lens) so that it is fully irradiated onto the photosensitive surface of the photodiode (PIN-PD or APD).

[0061] Photodiode model and performance parameters, for example, responsivity, dark current, and photosensitive surface area, are core performance indicators obtained from the photodiode product datasheet.

[0062] To achieve high-sensitivity detection, the following optimizations are required: High responsivity: for example, ≥0.5A / W at 550nm, which determines the efficiency of photoelectric conversion.

[0063] Extremely low dark current: for example, <1nA. This is the diode's own noise under no-light conditions, and the lower the value, the better.

[0064] Large photosensitive surface: to ensure that all light signals can be effectively collected.

[0065] Output current signal: A weak current signal proportional to the instantaneous value of the incident light power, typically measured in picoamperes or nanoamperes. This current signal is a physical quantity generated in real time by the photodiode after linearly converting the received "purified visible light" power according to its own responsivity parameters. Its magnitude is I_photo = R × P, where R is the responsivity and P is the incident light power.

[0066] The above process converts a light signal of a specific wavelength (500-600nm visible light) into a pure light signal through optical filtering (narrowband filter), and then generates a current signal that can be used for subsequent circuit processing through photoelectric conversion (photodiode). The output of each step strictly depends on its input and the inherent parameters of the core components, forming a clear and controllable signal chain.

[0067] Here, the voltage signal then enters a multi-stage amplification and conditioning phase. The system employs an instrumentation amplifier with a low noise figure and high common-mode rejection ratio (CMRR) for initial amplification, and introduces a level shifting circuit to adjust the signal to a voltage range suitable for subsequent processing. To further enhance the system's anti-interference capability, a differential signal conversion mechanism is specifically designed to convert the single-ended signal into a differential signal for transmission and processing. This measure can significantly suppress common-mode noise, improve signal integrity during transmission, and reduce the impact of environmental interference. The amplified and differentially processed analog signal is sampled and digitized by a high-resolution, low-integral-nonlinear analog-to-digital converter (ADC).

[0068] S104. Process the current signal to obtain a digital signal.

[0069] The processing includes electromagnetic shielding, I / V conversion, amplification and level shifting, differential conversion, and analog-to-digital conversion.

[0070] Electromagnetic shielding places the entire processing circuit inside a metal electromagnetic shielding cover.

[0071] I / V Conversion: A conversion circuit using a high-precision, low-bias-current operational amplifier converts a current signal into a voltage signal.

[0072] Amplification and Level Shifting: Amplification is performed using a low-noise, high common-mode rejection ratio instrumentation amplifier, and the voltage is adjusted to the input range (e.g., 0-3.3V) of the subsequent ADC (Analog-to-Digital Converter) through a level shifting circuit.

[0073] Differential conversion: Converting a single-ended signal into a differential signal using a differential amplifier.

[0074] Analog-to-digital conversion: Using a high-resolution ADC to sample and quantize differential signals.

[0075] Electromagnetic shielding effectiveness: This is a systematic parameter determined by the material, thickness, and structural integrity of the shield.

[0076] I / V conversion gain (feedback resistor value, such as 1MΩ, 1GΩ): This is a circuit parameter calculated and selected based on the expected current magnitude and the required output voltage range.

[0077] Amplification factor and level shift voltage: These are parameters determined through circuit design based on the output voltage of the preceding stage and the ADC range.

[0078] ADC resolution (e.g., 16-bit, 24-bit) and sampling rate: These are parameters obtained from the ADC chip datasheet and selected based on signal bandwidth and accuracy requirements.

[0079] Digital signal: This is a series of discrete digital values ​​output by the ADC that represent the original voltage signal.

[0080] Further, specifically, please refer to Figure 3 , Figure 3 The flowchart for obtaining digital signals provided in the embodiments of this application is as follows: Figure 3 As shown, the digital signal is obtained in the following way: S301. Convert the current signal into a voltage signal through a current-to-voltage conversion circuit.

[0081] Here, a high-precision, low-bias-current operational amplifier is used to construct a transimpedance amplifier circuit. The output of the photodiode is connected to the inverting input of the operational amplifier, and a high-resistance, low-temperature-coefficient precision feedback resistor is connected between the output and the inverting input.

[0082] The micro-current signal (nA / pA level) output by the photodiode is linearly converted into a voltage signal (mV level), which is the foundation for all subsequent voltage processing. A low-bias-current op-amp minimizes errors caused by the input current.

[0083] Feedback resistor (Rf), for example, 1 MΩ or 1 GΩ. This parameter is a circuit parameter calculated and selected based on the expected maximum photocurrent and the required output voltage range using Ohm's law V=I×Rf. For example, a 1 MΩ resistor is required to measure a 1 nanoamp current and generate a 1 millivolt voltage.

[0084] The op-amp bias current should be <1 pA. This parameter is a key performance indicator obtained from the op-amp's product datasheet and must be selected based on the signal magnitude; its value should be much smaller than the current being measured.

[0085] S302. Amplify and level-shift the voltage signal to adjust it to a preset voltage range.

[0086] The voltage signal after I / V conversion is sent to a low-noise, high common-mode rejection ratio instrumentation amplifier for initial amplification, and then a level shift circuit (usually composed of an operational amplifier and a resistor network) is cascaded to shift the voltage reference.

[0087] Amplify weak voltage signals to a suitable sampling amplitude to improve the system's signal-to-noise ratio and resolution; adjust AC signals containing positive and negative variations or unipolar signals referenced to ground to the optimal input range of the analog-to-digital converter (e.g., 0V to 3.3V) to avoid signal distortion.

[0088] For example, the gain can be 100x. This parameter is a system parameter determined based on the voltage amplitude after I / V conversion and the ADC range. Total gain = (ADC range) / (input signal range).

[0089] The preset voltage range is 0.5V to 2.5V. This range is set according to the input requirements of the selected ADC (such as unipolar 0-3.3V) and to allow for signal fluctuations.

[0090] S303: Convert the single-ended voltage signal after level shifting into a differential signal.

[0091] Using a differential amplifier or a dedicated differential driver, the single-ended voltage signal of a single reference point (ground) is converted into a pair of differential signals with equal amplitude and opposite phase. Differential transmission has a strong suppression effect on common-mode noise (such as power supply ripple and electromagnetic coupling noise), which can significantly improve the integrity of the signal during transmission to the ADC.

[0092] For example, the common-mode rejection ratio (CMRR) requirement is greater than 80 dB. This parameter is a key performance indicator given in the differential amplifier chip datasheet, reflecting its ability to suppress common-mode noise.

[0093] S304. Perform analog-to-digital conversion on the differential signal to obtain a digital signal.

[0094] The differential signal is directly connected to the positive and negative input terminals of a high-resolution, low-integral-nonlinear differential input ADC. The ADC samples and quantizes the signal, ultimately converting the analog differential voltage signal into a digital signal (a series of discrete digital codes) for subsequent digital processing and analysis by the host computer.

[0095] For example, the resolution of an ADC (Analog-to-Digital Converter) can be 16-bit or 24-bit. This parameter is a core specification obtained from the ADC chip datasheet; it determines the smallest voltage change the system can resolve and directly affects measurement accuracy. Higher resolution means a stronger ability to capture weak signals.

[0096] The sampling rate can be 1 kSPS (thousand samples per second). This parameter is set based on the frequency characteristics of the optical signal being measured (usually a slowly varying signal) and the real-time requirements of the system.

[0097] The digital signal (output) is a series of digital codes output by the ADC that represent the instantaneous value of the original differential voltage. It is the final result of the entire signal processing chain and provides the foundation for subsequent algorithm processing.

[0098] S105. Perform signal processing on the digital signal, including digital filtering and signal averaging, and invert and output the intensity information of the deep ultraviolet light source based on the processed data.

[0099] The digitized data is transmitted to the host computer system via an isolated communication interface to avoid noise introduced by ground loops. The host computer software platform integrates real-time signal processing algorithms, including digital filtering (such as adaptive filtering and wavelet denoising), baseline correction, signal averaging, and energy integration calculation, enabling accurate inversion and real-time display of the original ultraviolet light intensity. Users can monitor the light intensity change trend over time, set relevant parameters, perform system calibration, and export detection data and reports through a graphical human-machine interface.

[0100] In this step, adaptive filtering or wavelet denoising algorithms are run on the digital signal in the host computer to further suppress noise.

[0101] Signal averaging involves averaging the results of multiple samplings (e.g., 1000 times) to smooth out random noise; energy integration involves integrating the processed signal data over a period of time to obtain an integral value.

[0102] Inversion and Output: Multiply the integral value by a preset calibration coefficient to obtain the final intensity value, and then display or determine the alarm.

[0103] Filtering algorithm parameters (such as wavelet basis functions and thresholds): These are software parameters that are determined through simulation and experimental optimization during the algorithm development phase.

[0104] Average number of times (e.g., 1000 times): This is a software parameter set after balancing the need for signal-to-noise ratio improvement and the system's real-time requirements.

[0105] Calibration coefficients: These are system-level parameters (unit: intensity units / integral value) obtained by linear fitting after calibrating the entire system using a standard deep ultraviolet light source of known intensity.

[0106] Alarm threshold: This is a parameter set by the user based on the security or judgment criteria of the specific application scenario.

[0107] Here, the intensity information of the deep ultraviolet light source can be inverted and output in the following way: Energy integration is performed on the data after digital filtering and signal averaging.

[0108] Here, in the host computer software platform, the discrete digital sequence representing voltage changes over time, which has already undergone front-end processing (digital filtering, baseline correction, signal averaging), is summed or numerically integrated within a specific time window.

[0109] The total energy of the transient optical signal (manifested as a voltage signal) over a period of time is quantized to obtain a single integral value. The integration process itself is equivalent to a signal averaging, which can further suppress random noise and stabilize the final reading.

[0110] The digital sequence is data obtained by ADC sampling and preprocessed by the aforementioned algorithm, and is the direct input for energy integral calculation.

[0111] The integral value is a scalar value obtained by accumulating or numerically integrating all digital sequence values ​​within a specified time window using a software algorithm. It represents the total light energy detected during that time period.

[0112] Based on the results of energy integration calculations, the intensity information of the deep ultraviolet light source is inverted and output.

[0113] The dimensionless integral value is converted into a physically meaningful intensity value using preset calibration coefficients, and then intelligently judged and output.

[0114] Furthermore, the integral value obtained from the energy integral calculation is multiplied by a preset calibration coefficient to obtain the intensity value of the inverted deep ultraviolet light.

[0115] Perform a multiplication operation: Intensity value = integral value × calibration coefficient.

[0116] This completed the crucial transformation from "relative signal value" to "absolute physical quantity," giving the measurement results practical physical meaning and comparability.

[0117] The calibration parameter is a scaling factor that correlates the integral value with the intensity of deep ultraviolet light (unit: e.g., (W / cm²) / integral value or (photons / s) / integral value).

[0118] Calibration parameters can be obtained through system calibration experiments. The specific method is as follows: Irradiate the detection system with a standard deep ultraviolet light source of known intensity (calibrated with standard instruments), run the entire detection process to obtain a stable integral value, and then calculate the calibration coefficient using the formula: Calibration Coefficient = Known Standard Intensity / Measured Integral Value. This coefficient is stored in the system for subsequent measurements.

[0119] The intensity value of deep ultraviolet light is the final output physical quantity that reflects the true intensity of the incident deep ultraviolet light, which can be calculated in real time through the above multiplication operation.

[0120] Furthermore, it determines whether the intensity value of deep ultraviolet light exceeds a preset alarm threshold.

[0121] The alarm threshold is a user-defined intensity threshold value. It is manually set by the user through a graphical user interface on a host computer and stored as a parameter in the system, based on the safety standards, process requirements, or experimental needs of the specific application scenario. For example, in wafer defect detection, a defect is determined to exist when the intensity of scattered light exceeds a certain threshold.

[0122] If the alarm threshold is exceeded, an alarm message containing the intensity value will be generated and output; if the threshold is not exceeded, the intensity value of the deep ultraviolet light will be output directly as the intensity information.

[0123] For example, different branches are executed based on the judgment result.

[0124] The alarm branch can pop up an alert box on the main interface, change the indicator light color, record logs, and display the current intensity value at the same time.

[0125] The intensity value of a regular branch can be displayed or recorded in real time in the data display area of ​​the main interface.

[0126] The differentiated output method ensures that important anomalies are presented to users immediately and prominently, avoiding information omissions and providing clear and intuitive results feedback.

[0127] Here, the alarm information is a composite data body generated by software that contains specific warning content and the current intensity value.

[0128] Intensity information is the final output to the user, containing intensity values. It can be plain data or formatted display content.

[0129] In this way, this application endows pure digital signals with physical meaning and application intelligence through two key parameters: system calibration (calibration coefficient) and user setting (alarm threshold). The entire process is completed in the host computer through software algorithms, realizing the transformation from data to information, and from measurement to monitoring, thus completely solving the final application problem of weak light intensity detection.

[0130] The signal detection method, apparatus, electronic device, and medium provided in this application, by introducing ultraviolet-visible spectral conversion technology based on YAG-CE crystal and combining it with a multi-level noise suppression system of "optics-circuit-digital", solve the core problems of low quantum efficiency, high inherent noise, and susceptibility to electromagnetic interference in the detection of extremely weak deep ultraviolet light signals in the prior art. It achieves the direct technical effect of fundamentally improving detection sensitivity, significantly enhancing the anti-interference capability of the system, and ultimately realizing high signal-to-noise ratio and high stability detection.

[0131] The main technical advantages of this application lie in its organic integration of advanced materials science and electronic design. It achieves efficient ultraviolet-visible wavelength conversion through a YAG-CE crystal, breaking through the performance bottleneck of traditional detectors in the ultraviolet band. Through a comprehensive signal processing chain encompassing electromagnetic shielding, low-noise amplification, differential transmission, and digital processing, it significantly enhances the system's sensitivity and anti-interference capabilities. This device features a compact structure, stable performance, and wide applicability, especially meeting the urgent need for long-term, accurate, and reliable measurement of weak light signals in modern scientific research and industrial testing, providing an effective technical solution for high-end optical testing.

[0132] In this application, the ultraviolet-visible spectral conversion technology based on YAG-CE crystal is the primary prerequisite for achieving high sensitivity. This technology utilizes YAG-CE crystal to efficiently convert deep ultraviolet (DUV) photons, which are difficult to detect efficiently by silicon-based photoelectric sensors, into visible-band photons, fundamentally solving the core bottleneck of low efficiency in ultraviolet light detection and significantly improving the system's initial response capability to ultraviolet signals.

[0133] Comprehensive electromagnetic shielding and low-noise circuit design are the cornerstones of achieving high immunity. This technology encompasses end-to-end electromagnetic shielding packaging from the sensor to the processing circuit, and combines it with an I / V conversion circuit design based on a high-impedance, low-bias-current operational amplifier. The aim is to suppress external electromagnetic interference and inherent internal noise to the greatest extent possible at the physical level, ensuring the integrity of weak electrical signals.

[0134] The differential signal processing and transmission mechanism, following the amplification circuit, converts the single-ended voltage signal into a differential signal for further processing and transmission. It utilizes the excellent common-mode rejection ratio (CMRR) of differential amplification to effectively eliminate common-mode noise (such as power frequency interference) introduced in long-distance transmission or complex electromagnetic environments, greatly improving the system's stability and anti-interference capability.

[0135] The "aperture-filter" two-stage optical noise suppression technology combines a front-mounted micron-sized aperture with a narrowband filter targeting a specific wavelength of converted fluorescence, forming a two-stage optical filtering system. The aperture effectively limits stray light and improves spatial resolution, while the narrowband filter precisely filters out ambient background light noise. Working together, they provide the sensor with an extremely clean optical detection environment.

[0136] The digital signal processing and algorithm fusion technology performs secondary processing on the digitized signal at the host computer using specialized algorithms (such as digital filtering, signal averaging, and baseline correction). This software enhancement strengthens the noise immunity of the front-end hardware, further extracting noise-affected feature signals to maximize the final signal-to-noise ratio and providing flexible data analysis and display functions. These key technologies are interconnected and together constitute the solid technical barrier enabling this invention to achieve high sensitivity and high noise immunity.

[0137] Based on the same inventive concept, this application also provides a signal detection device corresponding to the signal detection method. Since the principle of the device in this application is similar to that of the signal detection method described above, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0138] Please see Figure 4 , Figure 4 This is a schematic diagram of the signal detection device provided in an embodiment of this application. Figure 4 As shown, the signal detection device 400 includes: Incident light receiving module 401 is used to receive incident light from a deep ultraviolet light source; The visible light signal acquisition module 402 is used to convert the incident light from the deep ultraviolet band to a visible light signal using a wavelength conversion crystal. The current signal conversion module 403 is used to pass the visible band optical signal through a narrow band filter and a photodiode in sequence to convert the optical signal into a current signal; The digital signal acquisition module 404 is used to process the current signal to obtain a digital signal; The intensity information output module 405 is used to perform signal processing on the digital signal, including digital filtering and signal averaging, and to invert and output the intensity information of the deep ultraviolet light source based on the processed data.

[0139] Furthermore, the current signal conversion module is also used to: receive the incident light in the deep ultraviolet band using the wavelength conversion crystal and absorb the deep ultraviolet photons, so that the electrons of the cerium ions in the wavelength conversion crystal transition from the ground state to the excited state. After a non-radiative process, the electrons transition from the excited state back to the ground state, releasing visible light photons with low energy and wavelengths within the preset wavelength range, thereby obtaining a visible light signal.

[0140] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of the electronic device provided in an embodiment of this application. Figure 5 As shown, the electronic device 500 includes a processor 510, a memory 520, and a bus 530.

[0141] Memory 520 stores machine-readable instructions executable by processor 510. When electronic device 500 is running, processor 510 and memory 520 communicate via bus 530. When the machine-readable instructions are executed by processor 510, they can perform the operations described above. Figure 1 The specific implementation of the signal detection method in the illustrated method embodiment can be found in the method embodiment, and will not be repeated here.

[0142] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described actions. Figure 1 The specific implementation of the signal detection method in the illustrated method embodiment can be found in the method embodiment, and will not be repeated here.

[0143] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0144] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interface; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0145] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0146] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0147] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0148] Finally, it should be noted that the above embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A signal detection method, characterized in that, include: Receives incident light from a deep ultraviolet light source; The incident light is converted from the deep ultraviolet band using a wavelength conversion crystal to obtain a visible light signal; The visible light signal is passed sequentially through a narrowband filter and a photodiode to convert the light signal into a current signal. The current signal is processed to obtain a digital signal; The digital signal is subjected to signal processing including digital filtering and signal averaging, and the intensity information of the deep ultraviolet light source is inverted and output based on the processed data.

2. The method according to claim 1, characterized in that, Visible light signals are obtained using the following methods: By using a wavelength conversion crystal to receive incident light in the deep ultraviolet band and absorb deep ultraviolet photons, the electrons of cerium ions in the wavelength conversion crystal are transitioned from the ground state to the excited state. After a non-radiative process, the electrons transition from the excited state back to the ground state, releasing visible light photons with low energy and wavelengths within a preset wavelength range, thus obtaining a visible light signal.

3. The method according to claim 2, characterized in that, The current signal is obtained in the following way: Visible light within a preset wavelength range is sequentially passed through a narrow-band filter to remove background noise and obtain purified visible light. The purified visible light is incident on a photodiode, which generates a current signal proportional to the light intensity.

4. The method according to claim 3, characterized in that, Digital signals are obtained in the following ways: The current signal is converted into a voltage signal through a current-to-voltage conversion circuit; The voltage signal is amplified and level-shifted to adjust it to a preset voltage range; The single-ended voltage signal after level shifting is converted into a differential signal; The differential signal is converted from analog to digital to obtain the digital signal.

5. The method according to claim 4, characterized in that, The intensity information of the deep ultraviolet light source is inverted and output using the following method: Energy integration calculation is performed on the data after digital filtering and signal averaging. Based on the results of energy integration calculation, the intensity information of the deep ultraviolet light source is inverted and output.

6. The method according to claim 5, characterized in that, The process of inverting and outputting the intensity information of the deep ultraviolet light source based on the energy integral calculation includes: The integral value obtained by the energy integral calculation is multiplied by a preset calibration coefficient to obtain the intensity value of the inverted deep ultraviolet light. Determine whether the intensity value of the deep ultraviolet light exceeds a preset alarm threshold; If the alarm threshold is exceeded, an alarm message containing an intensity value is generated and output. If the intensity is not exceeded, the intensity value of the deep ultraviolet light will be directly output as intensity information.

7. A signal detection device, characterized in that, include: An incident light receiving module is used to receive incident light from a deep ultraviolet light source; The visible light signal acquisition module is used to convert the incident light from the deep ultraviolet band to a visible light signal using a wavelength conversion crystal. A current signal conversion module is used to sequentially pass the visible band optical signal through a narrowband filter and a photodiode to convert the optical signal into a current signal; A digital signal acquisition module is used to process the current signal to obtain a digital signal; The intensity information output module is used to perform signal processing on the digital signal, including digital filtering and signal averaging, and to invert and output the intensity information of the deep ultraviolet light source based on the processed data.

8. The apparatus according to claim 7, characterized in that, The current signal conversion module is also used for: By using a wavelength conversion crystal to receive incident light in the deep ultraviolet band and absorb deep ultraviolet photons, the electrons of cerium ions in the wavelength conversion crystal are transitioned from the ground state to the excited state. After a non-radiative process, the electrons transition from the excited state back to the ground state, releasing visible light photons with low energy and wavelengths within a preset wavelength range, thus obtaining a visible light signal.

9. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is in operation, the processor communicates with the memory via the bus, and the processor executes the machine-readable instructions to perform the steps of the method as described in any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the method as described in any one of claims 1 to 6.

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