Effect of phase change shielding on the millisecond laser damage threshold of CMOS detectors

CMOS (complementary metal-oxide-semiconductor) detectors have become indispensable imaging units in spacecraft payloads, space-station instrumentation, and deep-space probes. In this study, we examine the damage mechanisms induced in CMOS detectors by 1064-nm laser irradiation under vacuum conditions. Finite-element simulations were employed to estimate the energy-density thresholds associated with pixel damage and the onset of the so-called platform threshold. The simulations indicate that 1064-nm pulsed laser exposure produces observable pixel damage when the incident fluence reaches approximately 130 mJ/cm². As the fluence approaches 500 mJ/cm², a phase transition in the diode layer gives rise to a pronounced "Plateau Threshold," causing the Sensor kill threshold to increase sharply. Experiments conducted in a vacuum establish the damage threshold of CMOS detectors subjected to millisecond 1064-nm laser pulses. The measurements reveal that multiple pulses can induce Sensor kill without exceeding the platform threshold, and that the eventual damage depth does not scale linearly with the nominal laser parameters due to the intrinsic characteristics of the 1064-nm wavelength. The experimental observations show strong agreement with the simulation-based predictions.