The miniaturization and integration of multispectral detectors have become one of the development directions for infrared detectors. This paper proposes a component structure that integrates a lens and window with airtight packaging, focusing on the characteristics of integrating low-temperature optical lenses for multispectral detectors. Various aspects are investigated, including high-precision optical alignment for different focal planes of the same component multispectral detector, low deformation filter support structure, and suppression of optical crosstalk and stray light. These studies address a series of issues related to high-precision alignment, low deformation filter support, prevention of optical crosstalk, and suppression of stray light in the miniaturization and integration packaging of multispectral detectors. The developed component has been successfully applied in a spectral imaging instrument for a specific project.

A component structure for a multispectral infrared detector with an integrated lens has been designed (Fig.3). The airtight packaging component structure of the multispectral infrared detector with an integrated lens includes a component housing, cover plate, lens, primary aperture, filter holder, filter, chip module, electrode plate, and filter holder support. Before packaging, the entire component is evacuated, followed by filling with inert gas, and finally sealed using parallel seam welding. The airtightness meets the long-term requirements of the payload.

By designing a three-layer laminated low-deformation multispectral filter holder assembly, multiple small filter pieces are adhered to the low-stress filter holder structure. This structure can also be used for the assembly of multiple mid-wave and long-wave filter pieces with the detector. It overcomes the problems of size interference and complex integration process with low yield associated with traditional bonding methods. It achieves the coupling of low-deformation multispectral filters with the detector (Fig.4).

This study employs the micro-adjustment technique for different focal planes of the multispectral infrared detector and the coaxial lens adjustment technique. It achieves a precision deviation of less than ±5 μm between different focal planes and the filter assembly for a three-band detector within the same component. The lens-to-detector alignment precision within ±15 μm is achieved (Table 1). Spectral tests are performed using the infrared detector component with an integrated lens, and the results indicate no significant optical crosstalk among channels (Fig.6).

Through the design of a three-layer laminated structure with low deformation, multiple small filters have been successfully bonded to the low deformation stress filter frame. The maximum low-temperature deformation of the 1.64 μm filter at 130 K is 0.9278 μm, while the maximum low-temperature deformation of the 2.13 μm and 1.38 μm filters at 130 K is 0.2292 μm (Fig.5). By using micro-adjustment techniques for different focal planes of the multi-band infrared detectors and coaxial lens adjustment techniques, the deviation in the alignment between different focal planes of the three-band detectors and the filters within the same component is better than ±5 μm, and the alignment precision between the lens and the detectors is better than ±15 μm. Spectral testing is conducted using the integrated lens infrared detector component. The results of the spectral testing indicate that there is no significant optical crosstalk among channels. A series of low-stress design and process improvements are applied to the low-temperature lens, and the results show that the band detection rate is greater than 1.5×10¹¹ cm·Hz^1/2·W^-1 (130 K). The maximum absolute variation in band response rate before and after rigorous environmental testing is 8.5% (Fig.9). The high-performance multi-spectral integrated infrared detector component is obtained, and the experimental results confirm that the detector functions properly and the component performs well (Table 2).

This article focuses on solving the packaging technology of multi-channel integrated infrared detector components, proposes a multi-band infrared detector airtightness packaging component with integrated lenses, and emphasizes the key technologies such as jointing of different focal planes for different bands and coaxial lens adjustment technology for the same component, high reliability support structure for multi-filter narrow seam splicing, and stray light suppression, solving the high-precision alignment of multi-channel integrated infrared detector components, low stress control, low optical crosstalk, low power consumption, and high reliability of the detector. A high-performance multi-band infrared detector component with integrated lenses has been obtained.