CCD(Charge Coupled Devices) is easily disturbed or dammed by laser because of high sensitivity. Based on the analyzing the factors that induce electric charges, the principles of MOS device were presented. The quantity of electric charges of MOS was simulated and the relationships of current and voltage in different laser pulse width and average power were studied. The experiment was carried out to investigate the characteristics of photoelectricity response at different laser parameters. Simulation results show that the charges of MOS device and the peak value of current and voltage increase as the average power or pulse width of laser increase accordingly. Meanwhile, the delay of current and voltage are displayed. The outcome of experiment reveals that the response threshold decreases when laser pulse width decreases correspondingly. The conclusions have certain significance to the application of ultrashort pulse in optical imaging.
