Laser Irradiation Of Tellurium Cadmium, Mercury And Photoelectric Detector Experiment

The photodetectors are widely applied in many fields for their merits. However, they can be easily damaged by high power laser, the research on the response character of the detectors to laser irradiation plays a very important role. The response characters of the middle-wave HgCdTe detector to the irradiation of in-band and off-band laser respectively are studied in details. The detectors' major response to the irradiation of in-band light is optical effect, while thermal effect can be seen when the incident laser power density is somewhat higher; when irradiated by off-band light, the detectors' major response is thermal effect. In detail, the major work that have been done are as follows:l.Irradiated by the 1.06 μ m 1.319 μ m 3.8 μ m laser respectively, when the incident laser power density is between the saturation threshold and the damage threshold, the vibrating phenomenon and the zero-output phenomenon can be seen in the PV-type detectors' response curve.2. Some experimental study on the vibrating phenomenon has been done primarily. We conclude that the output of laser is stable and the reason of vibrating phenomenon isn't the unstable incident laser.3.A reasonable explanation is given to the zero-output phenomenon.4. Some phenomena were observed when the HgCdTe(PC,PV) detectors were irradiated by off-band CW CO₂ laser which are much different from that when irradiated by in-band light. The irradiation of the off-band light can have a very strong disturbing effect on the detectors. A one-dimensional model is employed to do some work of qualitative and quantitative analysis for the experimental results. After study on the response character , we conclude that the detectors' major response to the irradiation of off-band light is thermal effect.