Experimental study on CMOS and materials irradiated by hundred-picosecond pulse laser with high repetition rate

Abstract

The imaging systems are widespread observation tools used in the national defense, industry and a number of aspects in science and technology. The CMOS image sensors which serve as the core part of optical imaging systems and detecting systems, are highly susceptible to laser interference and destruction. Therefore, it is of great theoretical and practical significance to study the damage characteristics of CMOS image sensor. There are many researches on the damage phenomena of CMOS image sensors irradiated by continuous laser, ns-laser, ms-laser and fs-laser, but the damage effects of CMOS irradiated by the hundred picoseconds fiber laser are few investigated. In this work, we used an all-fiber MOPA ps-pulsed laser system which generates pulse width of 226.5 ps and average power of 20 W with high beam quality and pulse stability to irradiate the CMOS at repetition rate of 9.6 MHz and 2.4 MHz. The experimental results showed that with the increase of laser power density, the phenomena of over saturation effect, saturated crosstalk effect, black line damage and black lines semi-cross damage appeared at different repetition rates. And the measured threshold and damage mechanism of CMOS were studied. Besides, based on the hydrodynamics theory, the laser-induced plasma density and temperature distribution of various materials (aluminum, copper and silicon) irradiated by the ps-laser were simulated, which provide a theoretical basis for the interaction of metals and semiconductors by the hundred picoseconds fiber laser