Research On The Weak Laser Pulse Detection Technology

In the field of detecting the weak laser pulse, there are still some shortcomings in the special equipments, such as high price, large size and small flexibility. Therefore, on the basis of the correlation detection technology, the digital orthogonal correlation detection technology was deeply studied and applied to the detection of weak laser pulse under the condition of background noises. Adopting the detection technology can suppress the background noises and improve the SNR. Moreover, using the DSP processor to realize the algorithm can make for developing an all-purpose, miniaturized, high-precision weak laser pulse detection system.In this paper, the digital orthogonal correlation detection technology was analyzed in theory and simulated by the Labview software, then the basic detection parameters were determined and the detection results were verified.The design of the whole hardware section in the detection system was accomplished. The whole hardware section consists of the photoelectronic pre-amplifier module and the DSP-based signal processing module. The design of each module refers to the circuit schematic analysis, the PCB design, the PCB welding and the circuit debugging. The experimental results show that the parameters of the two modules can meet the design requirements. For verifying the function of the DSP-based signal acquisition and processing module, the appropriate debugging programs were accomplished. Finally, the overall design plan of the software section was accomplished.The design of the software refers to the system initialization program, the data acquisition program, the digital signal processing program and the result output program. The function of each program was described and the corresponding program flowchart was accomplished.The experimental results show that the minimum detection power of the photoelectronic preamplifier module isμW order of magnitude and the detection relative error is within 0.23%～0.83%. In the DSP-based signal acquisition and processing module, the ADC whose resolution is 16 bit can meet the requirement of dual-channel synchronous sampling, and the output absolute error of DAC whose resolution is 12 bit is within 0.004～0.023V. The experimental data shows that the design of hardware section in the detection system is feasible. The work accomplished in this paper will provide an important basis for further writing software programs in the future, so as to form an all-purpose, portable, high-precision weak laser pulse detection system.