Experimental Study On The Coupling Rule Of Si Under Combined Laser Irradiation

Photoelectric detectors are widely used in military, civilian and many other fields. The studies of the irradiation effects and the damage mechanism of laser irradiation for photoelectric detectors are extensive and thorough, but the study of the effects by combined lasers irradiation is still few. From the existing literature and datum, we can only find the reflectance and transmission in the low laser power and most of the measure for reflectance is also based on the low power. In this paper,we have carried out the study on the experimental phenomenon and the measurement of the coupling coefficient of the photoelectric detectors with combined laser irradiated based on the integrating sphere. The main work that have been done are as follows:1.The interaction between semiconductor and laser is introduced, the absorption mechanism is explained; the integrating sphere and its application are introduced and its theory is deducted.2. In order to insure the experimental precision, above all, the detectors'linearity is calibrated. This paper carries out the absolute measurement of the reflectance and transmission of CdS and silicon based on the integrating sphere. CdS is irradiated by the in-band (632.8nm) and off-band (1319nm) laser, and the voltage responses of detector with the laser various power density is observed.3. Irradiation of 808nm,1319nm laser on Silicon are experimentally studied by double integrating sphere, The results show that the reflectivity for 808nm laser decrease with the 808nm laser's power increases and gradually reaches the saturated state, the coupling coefficient increases with the 808nm laser's power increasing and gradually reaches the saturated state, the reflectivity and transmissivity for 1319nm laser increase with the 1319nm laser's power increasing and gradually reach the saturated state,the interaction mechanism of two different wavelength lasers with Silicon is obviously different viewed on the rule.4. The silicon is simultaneously irradiated by the in-band (808nm) and off-band (1319nm) lasers, The results show that the reflectivity and transmissivity for 1319nm laser decrease and gradually reach the saturated state, and the coupling coefficient increases and gradually reaches the saturated state along with the 1319nm laser's power increasing when the 808nm laser power keeps constant; the reflectivity and transmissivity for the 1319nm laser decrease firstly and then increase and gradually reach the saturated state along with 808nm laser's power increasing when the 1319nm laser power keeps constant, and the coupling coefficient increase firstly and then decrease exponentially; It is showed that the absorption for off-band laser is enhanced with the in-band laser irradiated.5. The data error precision is analyzed, and the measurement error is no more than 0.005.