Research And Design Of Characteristics Testing System For Photoelectric Detectors

Photo detectors are key devices for photoelectric systems, it is necessary to haveknowledge of their characteristics, especially the spectral response characteristics. Thus it isvery important to design a characteristics test system for photo detectors.In this paper, a multifunctional photo detector characteristics testing system with widespectral range is proposed. With a spectral range from UV to IR, the system is applicable todifferent kinds of detectors such as photo diodes, photo transistors, photo PIN diodes, photocells and so forth. It can be used to test the spectral response characteristics, current-voltage(I-V) characteristics as well as illumination characteristics. The system adopts double beamsreplacement method to reduce the error brought by the instability and characteristic spectrumlines of the light source.In the system, a grating monochromator is used to obtain monochromatic beams, a DAmodule is utilized to get bias voltage, and the illumination can be tuned by a tunable aperture,two step motors are used to switch the detectors. The whole system is controlled by VC++designed software.In the end of the paper, the performances of a photo diode, a photo transistor and a PINdiode are tested using the system designed. The results are accurate, indicating that the systemis reliable to test the characteristics of various photo detectors.