The Research Of Electrically Tunable Infrared Spectral Chip-level-imaging Detection Technology

Spectral image detection approach, which combines common imaging detection technologies and optical filtering techniques, is a high-performance image information capturing means. Based on the spectral imaging information, the issues of not only the conventional images of targets but also the structural and material characters of objectives can be acquired. Recent years, the spectral imaging technology shows a broad applications and a huge commercial value in both military and civilian fields, and thus extensive concern. The research of the imaging method and critical technologies about electrically tunable infrared spectral chip-level-imaging detection has been conducted in this dissertation, and the electrically tunable mid-wavelength infrared(MWIR) and long-wavelength infrared(LWIR) optical filtering chips based on the Liquid-Crystal Fabry-Perot(LC-FP) optical interference structure has been designed and fabricated. The developed spectral chips can perform the operations of electrically tunable infrared wavelength based on the image processes or prior knowledge under the condition of directly inserting them into the imaging optical path or integrated with photosensitive array. The developed LC-FP filtering chips show several properties including smart architecture, low power consumption, high stability, strong environmental adaptability, high filling factor or light energy utilizing efficiency, low cost, and quick spectral response, and so on. The main work and innovation points of this dissertation are as follows:The architectures of electrically tunable LC-FP structures in MWIR and LWIR range based on zinc selenide(ZnSe)-based nano-aluminum(Al) film electrodes and silicon(Si)-based nano-gold(Au) film electrodes, has been constructed, respectively. Using the continuous elastomeric theory of nematic LC material and the algorithm of finite difference, the deflexion properties of LC cells under multi-voltage-driving-signal have been simulated, and the effective refractive index and the space distribution of layered LC material have been calculated; The transmission spectrum properties in MWIR and LWIR ranges have been simulated according to the algorithm of transfer matrix; The critical parameters, such as the film configuration, the structure size of LC microcavity, and so on, have been determined by further structural and parameter optimization.Considering the architectural features of the coupled infrared photosensitive array and effective encapsulation requirements, the morphology and structural size of the chips have been set; The issues including architecture design, fabrication, assessment and encapsulation of both the unit chip and block-addressable(4×4) LC-FP chip, have been completed based on standard microelectronic technologies.By contrasting and analyzing the infrared interference filtering measurements conducted in wide spectral region, the technological processes of the LC-FP chips have been optimized and further re-designed through introducing both experience parameters of ? and ?. Based on the developed unit spectral chip and block-addressable LC-FP chip, the infrared spectral image detection measurements of typical targets have been carried out, and continuously planned a roadmap of the technologies developed.