Research on packaging technology of infrared detectors integrated with cryogenic optical systems

This research proposes and executes a cryogenic optical system that is integrated with a long-focal-length infrared detector packaging technology to address the critical issues of detecting dim distant targets in deep space. The system effectively resolves technical bottlenecks in thermal deformation control, rapid cooling initiation, and miniaturization that are encountered in traditional cryogenic optical systems for long-focal-length integration by utilizing a diffractive-refractive hybrid optical design, elastic ring athermalization structure, and dual-cooler split cooling strategy. The system integrates a 256×256-pixel array detector with a total mass under 1 kg, reaches a focal length of 111 mm, and provides a full field of vision of 44°. It operates within the spectral region of 6.5-11 μm. The following are the primary innovations: (1) Low-temperature thermal bonding: Achieves a surface figure error of less than λ/6 and a lens thermal stress below 5 MPa under temperature changes of 150 K. (2) Split cooling strategy: Significantly reduces the thermal mass of the system by 26%, hence reducing the time required to initiate cooling while preserving thermal stability. (3) Enhanced energy concentration: Experimental validation has shown that the energy concentration efficiency exceeds 59.3%, yielding a lightweight, high-sensitivity infrared imaging system for deep-space exploration.