Life test research on the space-borne infrared detector for synchronization monitoring atmospheric corrector

The InGaAs infrared detector, as the core component of photoelectric conversion in the Synchronization Monitoring Atmospheric Corrector (SMAC), is responsible for measuring short-wave infrared spectral and polarization information. Among them, the service life of the thermoelectric cooler (TEC) poses a bottleneck for the overall lifespan of the infrared detector, and its reliability directly affects the normal operation of the detector. A thorough analysis is conducted for the working mechanism of the infrared detector utilized by SMAC and the failure mechanism of the TEC, and the lifetime characteristic of the product is comprehensively evaluated and analyzed through lifespan testing. To minimize time costs, an innovative accelerated lifetime test method is proposed, which utilizes temperature change rate as the accelerated stress. A lifetime test system is developed. Meanwhile, the dark current, relative spectral response, and cooling current of the infrared detector have been measured before and after the lifetime test based on the segmented uniform illumination light source. The experimental results reveal that after a cumulative lifetime test of approximately 120 days, the infrared detector underwent approximately 170,000 temperature cycles. The maximum delta value in the relative spectral responsivity of the infrared detector pre and post the life test is -1.86%, and the maximum increase in the TEC refrigeration drive current is 8.6%. The service life and performance changes of the detector could satisfy the requirements of space payloads. Moreover, the lifetime test system significantly improves test efficiency and exhibits excellent stability and scalability, fully capable of meeting the needs of lifetime tests under different temperature stress levels.