Wide Dynamic Range Photoelectric Signal Adaptive Processing Technical Research

The photoelectric detection system is used in various detection scenarios.The photodetector is the core device in the detection system.It has the advantages of fast response,small dark current and high quantum efficiency,and is widely used in various detection systems.It is limited by the factors of device material and structure.Under the influence of too large or too small external light intensity,the detector exists.Insufficient dynamic response timeliness,there will be problems such as device damage,output signal saturation,and weak signal annihilation due to excessive instantaneous photocurrent,which will greatly reduce the performance of the detection system.Therefore,the static operating point of the detector is improved.In a complex environment,it is the key to ensure system performance that it always works in a linear working area.In this paper,the bias control technology of photodetectors in the detection system is studied.Bias voltage control is commonly used in the analysis of detectors.On the basis of the scheme,a method is conceived and designed that converts the optical signal into an analog electrical signal input through photoelectric conversion,the mixed electrical signal is amplified and filtered,converted into a digital signal by analog-to-digital,and the digital signal is processed and judged by an algorithm,and the embedded processing unit controls the input.The bias output module adaptively adjusts the voltage output scheme.This paper introduces the detection principle of two different detection systems,analyzes the receptionThe important position of the optical system in the system composition,the important theoretical parameters of the detection system are theoretically calculated,and the temperature,polarization.The effect of pressure on detector performance.For the self-adaptive bias adjustment scheme of the photodetector,a transimpedance amplifier module,lock-in amplifier module,FPGA minimum system board,acquisition circuit module and bias output circuit module are designed.In this scheme,the light source selects a stable power of 650nm.It is generated by a semiconductor laser,and the incident light is vertically incident on the photosensitive surface of the detector after passing through the receiving optical system.Experiments show that the high linearity S2386-5K photodiode,as the photoelectric detection element of this system,can realize photoelectric signal conversion within the illumination range.The AD7606 acquisition chip has a sampling accuracy of up to 0.001V in the test,and can distinguish weak light intensity changes.The refresh rate of the DAC bias output module is maintained at 1.25MHz,which meets the adaptive adjustment time.Finally,after completing the necessary hardware circuit construction,sequential logic writing and interface design,through circuit testing and related simulation,The experimental results show that in the real-time change of external light intensity,the system achieves the effect of bias voltage adaptive adjustment,and the system performance is stable and the adaptive adjustment time is short,which verifies the basic logic function requirements expected by the design.