Research On Spectral Characteristics Of The Sillicon Photocell Test System

Silicon photodiode devices are widely used in photoelectric detection circuit because they enjoy the advantage of fast response, high sensitivity, stable performance, good linearity, low noise and easy integration with other semiconductor devices. The spectral characteristics of silicon photodetectors test system is designed and researched in this thesis in order to test the spectral sensitivity of the photodiode, propose a spectral application range, and give a scientific evaluation of the photodiodes in response to an increasing demand for optoelectronic devices and their components.This thesis expounds the design of the system from optical and electric system. As the core components of the optical system, the grating monochromator is being analyzed in spectral optical aspect. Signal conditioning circuit, data collection, and the design of the step motor control system are being introduced in the electric system. The FPGA, which is the core of the whole system, is used to communicate with the host computer after the process of the data which comes from the A/D. Then the grating monochromator is controlled by stepper motor to emit different frequencies of light, the stepper motor controller can receive commands from PC and control the stepper motor. The system is set up based on the principle of dual optical path substitution, and signal conditioning circuit is designed according to the correlative principles.After the analysis of the merits and the demerits of the various measurements of spectral responsively, the specification of the basic principles and the characteristics of photodetectors, and optical double substitution and cross-correlation principle on the basis of theoretical derivation, the present thesis further elaborates the general scheme of the system, the design of each component modules, hardware and software module, and concludes with the result of measurement and the relative spectral responsively curves.