Experimental Study On Enhancing The Absorption Of CdS Detector Under Combined Laser Irradiation

Photoelectric detectors are key components for carrying out photoelectron technology and photoelectric detection. They are widely used in national defense, industry, scientific technology and many fields. Because of high sensitivity, photoelectric detectors become chiefly aim attacked by laser weapons. So, the research on interaction of lasers with photoelectric detectors is of a great significance. Generally, we think the absorption coefficients of detector to off-band laser are very small. In order to reduce the damage threshold of weapon system, we hope to enhance the absorptions of detector by using a new irradiation way. In this paper, we study the irradiation effects of detector under combined lasers irradiation, and analyze a series of experimental phenomenas. The main work that have been done are as follows:1. With the semiclassical theory of free carrier and dispersion relation, optical absorption coefficient of free carrier was gained.2. 532nm laser as on-band laser, 1319nm laser as off-band laser, two lasers irradiated CdS photoresistance. One experiment was to observe the voltage responses of detector to the on-band laser power density change under the stated off-band laser power density; the other was to observe the voltage responses of detector to the off-band laser power density change under the stated on-band laser power density.3. The relative changes of reflection to on-band laser and off-band laser were measured. We can analyze the law of absorption changes by analyzing the relative changes of reflection. By comparing the voltage response curves of the detectors, we can know whether their laws were identical. Brief analysis had been done.4. Experimentally, to verify the effectivity of above irradiation method, the damage threshold was measured. With the change of 532nm laser power density, one experiment was to record the irradiation time of 1319nm laser when CdS photoresistance was damaged under the stated 1319nm laser power density; the other was to measure the 1319nm laser power density under the stated 1319nm laser irradiation time when CdS photoresistance was damaged.