Laser power measuring system
By using a photodetector, I/V converter, voltage signal processor, and V/F converter, combined with a PIN photodiode and a high-precision V/F conversion chip, the problems of high cost and low accuracy in laser power measurement systems are solved, achieving low-cost and high-precision laser power measurement.
Patent Information
- Application Number
- CN202422955137.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2034-12-02
AI Technical Summary
Existing laser power measurement systems are costly and have unsatisfactory measurement accuracy and anti-interference capabilities.
A photodetector, I/V converter, voltage signal processor, V/F converter and microprocessor are used to replace the high-resolution AD converter. PIN photodiodes and high-precision V/F conversion chips are used for voltage to frequency conversion.
This reduces costs while improving measurement accuracy and anti-interference capabilities, enabling high-precision laser power measurement.
Smart Images
Figure CN223756158U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to photoelectric equipment manufacturing technical field especially a system for measuring laser light output power. BACKGROUND
[0002] The current market laser light output power detection generally includes photoelectric detector, I / V converter, voltage signal processor, AD converter, microprocessor used in turn, adopts photoelectric detector to change the detected light signal into current signal, I / V converter carries out I / V (current voltage) conversion and exports voltage signal, and the voltage signal after processing through voltage signal processor is sent into AD converter and carries out analog-digital conversion, thereby calculating the laser power through microprocessor. The measurement precision depends on the A / D conversion chip in the high-resolution AD converter, and the high-precision high-resolution AD conversion chip is very expensive, which is not conducive to cost control, and the measurement precision and anti-interference are not ideal. SUMMARY
[0003] The utility model solves the problem of providing a laser power measurement system to solve the problem of high cost, low measurement precision and poor anti-interference of the existing laser power measurement system.
[0004] In order to solve the above problem, the technical scheme of the utility model is: the laser power measurement system includes photoelectric detector, I / V converter, voltage signal processor, V / F converter and microprocessor used in turn.
[0005] In the above technical scheme, the more specific scheme can be: the photoelectric detector is PIN photodiode.
[0006] Further, the spectral range of the PIN photodiode is 400-1100nm.
[0007] Further, the V / F conversion chip of the V / F converter has a maximum output frequency of 100KHZ, and the linearity is up to 0.01%.
[0008] Further, the voltage signal processor includes an amplifier and a filter.
[0009] Compared with the prior art, the utility model has the following beneficial effects due to the adoption of the above technical scheme:
[0010] 1. The laser power measurement system changes the original AD conversion (analog-digital conversion) into V / F conversion (voltage to frequency), which improves the measurement precision and anti-interference on the basis of reducing the manufacturing cost.
[0011] 2. This laser power measurement system uses a PIN photodiode with a spectral range of 400–1100 nm as the photodetector, which has a high degree of matching between the photodiode wavelength and the absorption rate, and a high degree of positive correlation between the absorption source and the light energy.
[0012] 3. This laser power measurement system uses a V / F conversion chip with a maximum output frequency of 100kHz and a linearity of up to 0.01%. It features high resolution, good linearity, and low cost. The frequency of its output pulse train changes precisely proportionally to the voltage applied at the input terminal, demonstrating the unique advantages of the voltage / frequency converter. It can be used as a low-cost analog-to-digital converter in microprocessor control systems. Attached Figure Description
[0013] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;
[0014] Figure 2 This is a graph showing the relationship between the wavelength and absorptivity of the photodiode in the photodetector of this utility model embodiment;
[0015] Figure 3 This is a graph showing the relationship between the absorbed photocurrent and light energy of the photodetector in an embodiment of this utility model.
[0016] The diagram shows: 1. Photodetector; 2. I / V converter; 3. Voltage signal processor; 3-1. Amplifier; 3-2. Filter; 4. V / F converter; 5. Microprocessor. Detailed Implementation
[0017] The embodiments of this utility model will be further described in detail below with reference to the accompanying drawings:
[0018] like Figure 1 The laser power measurement system shown includes a photodetector 1, an I / V converter 2, a voltage signal processor 3, a V / F converter 4, and a microprocessor 5 used in sequence. The original AD conversion (analog-to-digital conversion) is replaced with V / F conversion (voltage-to-frequency conversion), which improves both measurement accuracy and anti-interference ability while reducing manufacturing costs.
[0019] Photodetector 1 uses a PIN photodiode, widely used in optical power design for its low dark current, high sensitivity, and ability to operate in a zero-bias state. Currently used PIN diodes are mainly made of materials such as Si, Ge, and Ingaas, covering a wavelength range from 400 to 1800 nm. Here, a PIN photodiode with a spectral range of 400-1100 nm is selected. This type of PIN photodiode has a high degree of matching between photodiode wavelength and absorptivity, and a high positive correlation between the absorbed light source and light energy. Figure 2 , Figure 3 As shown.
[0020] I / V converter 2, the photodetector 1 converts the optical signal into a current signal, and a I / V conversion circuit is used in the front end to collect the current signal and convert it into a corresponding voltage signal. A current / voltage converter (I / V converter) accepts an input current I and forms an output voltage V=AI, where A is the circuit gain, measured in V / A. After the PIN photodiode receives light, it generates a current Id proportional to the light intensity. After the I / V conversion circuit, the current Id is converted into an output voltage Vo, Vo = Id ×Rf.
[0021] The voltage signal processor 3 includes an amplifier 3-1 and a filter 3-2, which filters and amplifies the voltage signal output by the I / V conversion.
[0022] V / F converter 4, the signal after amplification and filtering is sent to the V / F conversion circuit for voltage / frequency conversion, converting the analog quantity into a digital square wave for easy data acquisition and processing by the single-chip microcomputer. Since the incident light is stable, the conversion speed of the V / F device is not high, but the precision is very high, and the dynamic range of the signal is very large. Here, a V / F chip is selected, which has high resolution, good linearity, low cost, etc. The maximum output frequency is 100KHZ, and the linearity is as high as 0.01%. The frequency of the output pulse chain is accurately proportional to the voltage applied to the input end, which reflects the unique advantage of the pressure / frequency converter, which can be used as a low-cost analog-to-digital converter in a microprocessor control system.
[0023] Microprocessor 5, i.e. MCU, the data processing of the MCU microprocessor is the core part of realizing the optical power measurement. Here, the square wave converted from the V / F conversion needs to be frequency measured, and the digital quantity of the frequency needs to be data processed and calibrated and corrected, and finally converted into a laser power value.
[0024] Working principle: the photodetector 1 converts the detected optical signal into a current signal, the I / V converter 2 converts the I / V (current voltage) into a voltage signal, and then the voltage signal processor 3 amplifies and filters the voltage signal through the amplifier 3-1 and the filter, and then sends it to the V / F converter 4 to convert the voltage into a frequency square wave. The microprocessor 5 calculates the square wave frequency, and then calculates the laser power according to the linear proportional relationship between the voltage and the square wave frequency after calibration and correction.
[0025] Using the laser power measurement system to detect the laser power, the measurement is accurate, the precision is high, and the cost is low.
Claims
1. A laser power measurement system, characterized by: It comprises photoelectric detector, I / V converter, voltage signal processor, V / F converter and microprocessor used in sequence.
2. The laser power measurement system of claim 1, wherein: The photoelectric detector is PIN photodiode.
3. The laser power measurement system of claim 2, wherein: The spectrum range of the PIN photodiode is 400-1100 nm.
4. The laser power measurement system of any of claims 1-3, wherein: The maximum output frequency of the V / F conversion chip of the V / F converter is 100 KHZ, and the linearity is up to 0.01%.
5. The laser power measurement system of any of claims 1-3, wherein: The voltage signal processor comprises amplifier and filter.
6. The laser power measurement system of claim 4, wherein: The voltage signal processor comprises amplifier and filter.