An optical power harvesting device and method

Abstract

The application discloses an optical power collection device and method, relates to the technical field of optical signal detection, and comprises the following: a photoelectric detector for converting an optical signal into a current signal; a transimpedance amplifier for converting the current signal into a pulse voltage signal; a peak detector for detecting the peak value of the pulse voltage signal; an RC filter network for filtering noise of the pulse voltage signal; a low-frequency amplifier for amplifying the low-frequency pulse voltage signal; an ADC collection module for converting the amplified pulse voltage signal into a digital signal; a first feedback network for adjusting the gain of the transimpedance amplifier; a second feedback network for adjusting the gain of the low-frequency amplifier; and a microcontroller for controlling the first feedback network to adjust the gain of the transimpedance amplifier according to the peak value of the pulse voltage signal and for controlling the second feedback network to adjust the gain of the low-frequency amplifier according to the digital signal.

Description

Technical Field

[0001] This application relates to the field of optical signal detection technology, and in particular to an optical power acquisition device and method. Background Technology

[0002] During the acquisition of pulsed optical power, the feedback networks of the high-speed transimpedance amplifier (TIA) and the low-frequency amplifier are usually fixed parameters. When the intensity of the input optical signal changes, the fixed feedback network cannot perfectly match the signal amplitude, which leads to distortion and affects the accuracy of the subsequent analog-to-digital converter (ADC) acquisition module.

[0003] Therefore, based on the above problems, there is an urgent need to provide an optical power acquisition device and method that can improve the acquisition accuracy of optical power. Summary of the Invention

[0004] The purpose of this application is to provide an optical power acquisition device and method that can improve the acquisition accuracy of optical power.

[0005] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides an optical power acquisition device, comprising: a photodetector, a transimpedance amplifier, a peak detector, an RC filter network, a low-frequency amplifier, an ADC acquisition module, a microcontroller, a first feedback network, and a second feedback network. The photodetector is used to acquire optical signals and convert the optical signals into current signals. The input terminal of the transimpedance amplifier is connected to the output terminal of the photodetector, and is used to convert the current signal into a pulse voltage signal. The input terminal of the peak detector is connected to the output terminal of the transimpedance amplifier, and is used to detect the peak value of the pulse voltage signal; The input terminal of the RC filter network is connected to the output terminal of the transimpedance amplifier to filter out noise from the pulse voltage signal and obtain a low-frequency pulse voltage signal. The input terminal of the low-frequency amplifier is connected to the output terminal of the RC filter network to amplify the low-frequency pulse voltage signal and obtain the amplified pulse voltage signal. The input terminal of the ADC acquisition module is connected to the output terminal of the low-frequency amplifier, and is used to convert the amplified pulse voltage signal into a digital signal. The first feedback network is connected to the feedback terminal of the transimpedance amplifier and is used to adjust the gain of the transimpedance amplifier; The second feedback network is connected to the feedback terminal of the low-frequency amplifier and is used to adjust the gain of the low-frequency amplifier; The microcontroller is connected to the peak detector, the ADC acquisition module, the first feedback network, and the second feedback network, respectively, and is used to control the first feedback network to adjust the gain of the transimpedance amplifier according to the peak value of the pulse voltage signal; and to control the second feedback network to adjust the gain of the low-frequency amplifier according to the digital signal.

[0006] Optionally, the microcontroller's processing includes: When the peak value of the pulse voltage signal exceeds the first preset range threshold, the gain of the transimpedance amplifier is reduced. When the peak value of the pulse voltage signal is less than the first preset range threshold, the gain of the transimpedance amplifier is increased. When the voltage value corresponding to the digital signal is greater than the second preset range threshold, the gain of the low-frequency amplifier will be reduced. When the voltage value corresponding to the digital signal is less than the second preset range threshold, the gain of the low-frequency amplifier is increased.

[0007] Optionally, the photodetector is a photodiode.

[0008] Optionally, the first preset range threshold is 0mv-120mv.

[0009] Optionally, the second preset range threshold is 120mv-3000mv.

[0010] Optionally, the low-frequency amplifier is a non-inverting amplifier; the non-inverting amplifier includes multiple operational amplifiers.

[0011] Optionally, the peak detector is a peak hold circuit; the peak hold circuit includes an operational amplifier, a diode, and a capacitor connected in series.

[0012] Optionally, the first feedback network includes multiple parallel resistor branches; each resistor branch includes a resistor and a switching transistor connected in series; the switching transistor is connected to a microcontroller.

[0013] Optionally, the second feedback network includes multiple parallel resistor branches; each resistor branch includes a resistor and a switching transistor connected in series; the switching transistor is connected to the microcontroller.

[0014] Secondly, this application provides an optical power acquisition method, including: Optical signals are acquired using photodetectors and then converted into electrical signals. A transimpedance amplifier is used to convert the current signal into a pulse voltage signal; and a peak detector is used to determine the peak value of the pulse voltage signal. Based on the peak value, the gain of the transimpedance amplifier is adjusted by using a microcontroller to control the first feedback network. The pulse voltage signal is filtered using an RC filter network to obtain a low-frequency pulse voltage signal; The low-frequency pulse voltage signal is amplified using a low-frequency amplifier to obtain the amplified pulse voltage signal; The amplified pulse voltage signal is converted into a digital signal using an ADC acquisition module. Based on the digital signal, the gain of the low-frequency amplifier is adjusted by using a microcontroller to control the second feedback network, thereby realizing optical power acquisition; Multiple optical power acquisitions were performed to obtain the corresponding digital signals, and the average value of the digital signals was determined. The optical power is determined based on the mean of the digital signal, the current gain of the transimpedance amplifier, and the current gain of the low-frequency amplifier.

[0015] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides an optical power acquisition device and method. It achieves precise acquisition and conversion of optical signals by using a high-response photodetector (PD). A transimpedance amplifier converts the current signal into a pulse voltage signal, and an RC filter network is used to filter out noise from the pulse voltage signal, improving noise suppression capability and increasing the acquisition accuracy of the optical signal. A low-frequency amplifier amplifies the low-frequency pulse voltage signal, enhancing its amplitude. An ADC acquisition module converts the amplified pulse voltage signal into a digital signal, enabling optical power acquisition. A microcontroller unit (MCU) controls a first feedback network to adjust the gain of the transimpedance amplifier, and simultaneously controls a second feedback network to adjust the gain of the low-frequency amplifier, constraining the pulse voltage signal and digital signal within a specific range. This improves the accuracy and fidelity of the digital signal, achieves dynamic adjustment of the first and second feedback networks, expands the dynamic range of the optical power acquisition device, and further improves the acquisition accuracy of the optical power. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0017] Figure 1 This is a schematic diagram of an optical power acquisition device module in one embodiment of this application; Figure 2 This is a schematic diagram illustrating the linear relationship between optical power and the amplified pulse voltage signal in one embodiment of this application; Figure 3 This is a schematic diagram of an optical power acquisition method in one embodiment of this application. Detailed Implementation

[0018] 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.

[0019] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] In one exemplary embodiment, such as Figure 1 As shown, an optical power acquisition device is provided, including: a photodetector, a transimpedance amplifier, a peak detector, an RC filter network, a low-frequency amplifier, an ADC acquisition module, a microcontroller, a first feedback network, and a second feedback network.

[0021] A photodetector is used to acquire optical signals and convert them into electrical signals. Specifically, a photodetector is a photodiode; the optical signal is a high-speed pulsed optical signal.

[0022] The input of the transimpedance amplifier is connected to the output of the photodetector to convert the current signal into a pulse voltage signal.

[0023] The input of the peak detector is connected to the output of the transimpedance amplifier to detect the peak value of the pulse voltage signal. Specifically, the peak detector is a peak hold circuit; the peak hold circuit includes an operational amplifier, a diode, and a capacitor connected in series.

[0024] The input of the RC filter network is connected to the output of the transimpedance amplifier to filter out noise from the pulse voltage signal, obtaining a low-frequency pulse voltage signal. Specifically, the RC filter network is used to filter out high-frequency noise from the pulse voltage signal.

[0025] The input of the low-frequency amplifier is connected to the output of the RC filter network to amplify the low-frequency pulse voltage signal, obtaining the amplified pulse voltage signal. The low-frequency amplifier in this application is a non-inverting amplifier; the non-inverting amplifier includes multiple operational amplifiers.

[0026] The input terminal of the ADC acquisition module is connected to the output terminal of the low-frequency amplifier to convert the amplified pulse voltage signal into a digital signal.

[0027] The first feedback network is connected to the feedback terminal of the transimpedance amplifier and is used to adjust the gain of the transimpedance amplifier. In this application, the first feedback network includes multiple parallel resistor branches; each resistor branch includes a resistor and a switching transistor connected in series; the switching transistor is connected to a microcontroller.

[0028] The second feedback network is connected to the feedback terminal of the low-frequency amplifier and is used to adjust the gain of the low-frequency amplifier. In this application, the second feedback network includes multiple parallel resistor branches; each resistor branch includes a resistor and a switching transistor connected in series; the switching transistor is connected to a microcontroller.

[0029] The microcontroller is connected to the peak detector, the ADC acquisition module, the first feedback network, and the second feedback network, respectively. It is used to control the first feedback network to adjust the gain of the transimpedance amplifier according to the peak value of the pulse voltage signal, and to control the second feedback network to adjust the gain of the low-frequency amplifier according to the digital signal.

[0030] Specifically, the microcontroller receives the peak value of the pulse voltage signal determined by the peak detector. When the peak value of the pulse voltage signal is greater than a first preset range threshold, it controls the first feedback network to decrease the gain of the transimpedance amplifier; when the peak value of the pulse voltage signal is less than the first preset range threshold, it controls the first feedback network to increase the gain of the transimpedance amplifier. In this application, the first preset range threshold is 0mV-120mV.

[0031] The microcontroller receives the digital signal determined by the ADC acquisition module and determines the corresponding voltage value based on the digital signal. When the voltage value corresponding to the digital signal is greater than a second preset range threshold, the microcontroller controls the second feedback network to decrease the gain of the low-frequency amplifier; when the voltage value corresponding to the digital signal is less than the second preset range threshold, the microcontroller controls the second feedback network to increase the gain of the low-frequency amplifier. In this application, the second preset range threshold is 120mV-3000mV.

[0032] In addition, the microcontroller is also used to initialize and set the default states of the first and second feedback networks.

[0033] The process of acquiring optical signals using an optical power acquisition device and obtaining the corresponding digital signals constitutes one optical power acquisition. By repeating the acquisition process, the average power of the pulsed light can be obtained.

[0034] The relationship between optical power y and the amplified pulse voltage signal x is linear, such as... Figure 2 As shown, R represents the perfectly fitted data.

[0035] In one exemplary embodiment, such as Figure 3 As shown, an optical power acquisition method is provided. This method utilizes optical power acquisition and specifically includes the following steps S1 to S9. Wherein: S1: Use a photodetector to acquire optical signals and convert them into current signals.

[0036] Before acquiring the optical signal, the optical power acquisition device is first initialized using a microcontroller, and the first and second feedback networks are set to their default states.

[0037] The optical signal is acquired using a photodetector, converted into a current signal, and then sent to a transimpedance amplifier.

[0038] S2: Use a transimpedance amplifier to convert the current signal into a pulse voltage signal; and use a peak detector to determine the peak value of the pulse voltage signal.

[0039] After receiving a current signal, the transimpedance amplifier converts it into a pulse voltage signal, which is then split into two paths: one path is input to an RC filter network, and the other path is input to a peak detector. The peak detector detects the peak value (peak voltage) of the pulse voltage signal and sends the peak value to the microcontroller.

[0040] S3: Based on the peak value, the gain of the transimpedance amplifier is adjusted by using a microcontroller to control the first feedback network.

[0041] After receiving the peak value sent by the peak detector, the microcontroller determines whether the peak value is within the first preset range threshold. If the peak value is greater than the first preset range threshold, the microcontroller controls the first feedback network to switch to a smaller feedback resistor to reduce the gain of the transimpedance amplifier. If the peak value is less than the first preset range threshold, the microcontroller controls the first feedback network to switch to a larger feedback resistor to increase the gain of the transimpedance amplifier, so as to ensure that the pulse voltage signal output by the low transimpedance amplifier is always within the first preset range threshold.

[0042] S4: Use an RC filter network to filter the pulse voltage signal to obtain a low-frequency pulse voltage signal.

[0043] The RC filter network receives the pulse voltage signal sent by the transimpedance amplifier and filters out the high-frequency noise in the pulse voltage signal to obtain a low-frequency pulse voltage signal, which is then sent to the low-frequency amplifier.

[0044] S5: Use a low-frequency amplifier to amplify the low-frequency pulse voltage signal to obtain the amplified pulse voltage signal.

[0045] S6: Use the ADC acquisition module to convert the amplified pulse voltage signal into a digital signal.

[0046] S7: Based on the digital signal, the gain of the low-frequency amplifier is adjusted by using a microcontroller to control the second feedback network, thereby realizing optical power acquisition.

[0047] The microcontroller receives the digital signal sent by the ADC acquisition module and determines the corresponding voltage value. It then checks if the voltage value is within a second preset threshold range (e.g., 20%-80% of the ADC acquisition module's full-scale range). If the voltage value is greater than the threshold, the microcontroller controls the second feedback network to switch to a smaller feedback resistor, reducing the gain of the low-frequency amplifier. If the voltage value is less than the threshold, the microcontroller controls the second feedback network to switch to a larger feedback resistor, increasing the gain of the low-frequency amplifier. This ensures that the amplified pulse voltage signal output by the low-frequency amplifier can be accurately acquired by the ADC acquisition module, avoiding ADC saturation or excessive quantization error.

[0048] S8: Perform multiple optical power acquisitions to obtain the corresponding digital signals and determine the average value of the digital signals.

[0049] The cyclic acquisition process ensures continuous and accurate measurement of the average power of the optical signal, making this application applicable to the detection of optical signals with various intensity variations.

[0050] S9: Determine the optical power based on the mean of the digital signal, the current gain of the transimpedance amplifier, and the current gain of the low-frequency amplifier.

[0051] Specifically, the optical power acquisition process is repeated. Whenever the intensity of the input optical signal changes, the microcontroller readjusts the first and second feedback networks to ensure that the optical power acquisition device is always in optimal condition. The microcontroller accumulates multiple digital signals acquired by the ADC acquisition module, calculates the average voltage, and then converts it into average optical power based on the gain of the transimpedance amplifier and the low-frequency amplifier.

[0052] This application achieves adjustable repetition rate (RF) from 200kHz to 1MHz and adjustable pulse width (PWM) from 100µs to 400µs under high-speed pulsed light input conditions. With a total input signal power range of -3 to -28dBm, this application can accurately acquire optical signals without distortion. A high-response photodetector is used in conjunction with a high-speed transimpedance amplifier to convert weak optical signals into pulsed voltage signals. By optimizing the bandwidth and noise suppression capability of the preamplifier circuit, the dynamic response capability of the optical power acquisition device to pulsed voltage signals is improved. Real-time gain adjustment in the control loop enhances the acquisition accuracy of the photodetector for high-speed pulsed light signals, thereby achieving fast and stable gain adjustment control and ensuring that the optical power acquisition device can accurately acquire optical power even when the input optical power changes.

[0053] When the duty cycle of an optical signal is small, its peak power is high but its average power is low. This means that when acquiring an optical signal, the photodetector must be able to withstand instantaneous high-intensity light impacts to accurately capture the peak signal, while maintaining sufficient sensitivity to weak signals (optical signals with power below the average power) to avoid saturation distortion at high peak power and failure to identify valid signals due to noise in the low average power range. When the duty cycle of an optical signal is large, its peak power is low but its average power is high. In this case, the photodetector will keenly capture the characteristics of optical signals with higher average power, and then appropriately reduce the gain through a feedback mechanism to avoid circuit noise accumulation and signal oversaturation caused by prolonged high power input. This ensures that the output digital signal always stays within the linear operating range, maintaining the stability and accuracy of the measurement data.

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. 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. In summary, the content of this specification should not be construed as a limitation of this application.

Claims

1. An optical power acquisition device, characterized in that, The optical power acquisition device includes: a photodetector, a transimpedance amplifier, a peak detector, an RC filter network, a low-frequency amplifier, an ADC acquisition module, a microcontroller, a first feedback network, and a second feedback network. The photodetector is used to acquire optical signals and convert the optical signals into current signals. The input terminal of the transimpedance amplifier is connected to the output terminal of the photodetector, and is used to convert the current signal into a pulse voltage signal. The input terminal of the peak detector is connected to the output terminal of the transimpedance amplifier, and is used to detect the peak value of the pulse voltage signal; The input terminal of the RC filter network is connected to the output terminal of the transimpedance amplifier to filter out noise from the pulse voltage signal and obtain a low-frequency pulse voltage signal. The input terminal of the low-frequency amplifier is connected to the output terminal of the RC filter network to amplify the low-frequency pulse voltage signal and obtain the amplified pulse voltage signal. The input terminal of the ADC acquisition module is connected to the output terminal of the low-frequency amplifier, and is used to convert the amplified pulse voltage signal into a digital signal. The first feedback network is connected to the feedback terminal of the transimpedance amplifier and is used to adjust the gain of the transimpedance amplifier; The second feedback network is connected to the feedback terminal of the low-frequency amplifier and is used to adjust the gain of the low-frequency amplifier; The microcontroller is connected to the peak detector, the ADC acquisition module, the first feedback network, and the second feedback network respectively, and is used to control the first feedback network to adjust the gain of the transimpedance amplifier according to the peak value of the pulse voltage signal; and to control the second feedback network to adjust the gain of the low-frequency amplifier according to the digital signal. The microcontroller's processing includes: When the peak value of the pulse voltage signal exceeds the first preset range threshold, the gain of the transimpedance amplifier is reduced. When the peak value of the pulse voltage signal is less than the first preset range threshold, the gain of the transimpedance amplifier is increased. When the voltage value corresponding to the digital signal is greater than the second preset range threshold, the gain of the low-frequency amplifier will be reduced. When the voltage value corresponding to the digital signal is less than the second preset range threshold, the gain of the low-frequency amplifier is increased.

2. The optical power acquisition device according to claim 1, characterized in that, The photodetector is a photodiode.

3. The optical power acquisition device according to claim 1, characterized in that, The first preset range threshold is 0mv-120mv.

4. The optical power acquisition device according to claim 1, characterized in that, The second preset range threshold is 120mv-3000mv.

5. The optical power acquisition device according to claim 1, characterized in that, The low-frequency amplifier is a non-inverting amplifier; the non-inverting amplifier includes multiple operational amplifiers.

6. The optical power acquisition device according to claim 1, characterized in that, The peak detector is a peak hold circuit; the peak hold circuit includes an operational amplifier, a diode, and a capacitor connected in series.

7. The optical power acquisition device according to claim 1, characterized in that, The first feedback network includes multiple parallel resistor branches; each resistor branch includes a resistor and a switching transistor connected in series; the switching transistor is connected to a microcontroller.

8. The optical power acquisition device according to claim 1, characterized in that, The second feedback network includes multiple parallel resistor branches; each resistor branch includes a resistor and a switching transistor connected in series; the switching transistor is connected to the microcontroller.

9. A method for acquiring optical power, applied to the optical power acquisition device according to any one of claims 1-8, characterized in that, The optical power acquisition method includes: Optical signals are acquired using photodetectors and then converted into electrical signals. A transimpedance amplifier is used to convert the current signal into a pulse voltage signal; and a peak detector is used to determine the peak value of the pulse voltage signal. Based on the peak value, the gain of the transimpedance amplifier is adjusted by using a microcontroller to control the first feedback network. The pulse voltage signal is filtered using an RC filter network to obtain a low-frequency pulse voltage signal; The low-frequency pulse voltage signal is amplified using a low-frequency amplifier to obtain the amplified pulse voltage signal; The amplified pulse voltage signal is converted into a digital signal using an ADC acquisition module. Based on the digital signal, the gain of the low-frequency amplifier is adjusted by using a microcontroller to control the second feedback network, thereby realizing optical power acquisition; Multiple optical power acquisitions were performed to obtain the corresponding digital signals, and the average value of the digital signals was determined. The optical power is determined based on the mean of the digital signal, the current gain of the transimpedance amplifier, and the current gain of the low-frequency amplifier.

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