Mid-wave infrared focal plane detectors have been widely concerned because of their importance in military fields such as infrared guided missiles and infrared night vision devices, where the bandpass filter film has the function of filtering stray light and protecting detectors. The purpose of this study is to prepare high-performance bandpass filter film for mid-wave infrared focal plane detectors through analysis, material selection and optimization, aiming at the key technical problems of mid-infrared focal plane detector filter film. With Ge as the high refractive index material and substrate and SiO as the low refractive index material, the band-pass film system structure is designed, which not only realizes the high transmittance of 295－505 m band greater than 92% and the passband width is better than 37－48 m at 0° incidence angle. Moreover, it can achieve good cutoff effect for other bands except 295－505 m. The test results show that it has good properties such as smoothness, solidity and so on. Therefore, the filter film can be well applied to mid-wave infrared focal plane detectors.

Infrared imaging technology is widely used in many fields, but the non-uniformity of the design and manufacturing process seriously reduces the imaging quality of infrared images. To solve this problem, an infrared image correction system based on FPGA is designed. The system uses a two-point correction algorithm to update the pixel gain and bias of a domestic short-wave detector, then uses the 3σ algorithm to detect blind pixels and uses the idea of domain substitution to correct the blind pixels. The blind pixels are replaced by the values of valid pixels around the blind pixels in proportion to reduce the operational complexity. Experiments are carried out on the hardware system based on XC5VLX110T FPGA. The results show that the designed infrared image correction system can improve the image non-uniformity, the image quality and the imaging speed. In addition, the abundant spare resources make the system have better expansibility. This system has certain application value in infrared image processing.

With the continuous expansion of the array size of infrared focal plane detectors, the reliability failure of dewar caused by low-temperature thermal mismatch deformation of multi-layer structures is becoming increasingly prominent, and the demand for quantitative characterization of low-temperature deformation of the focal plane is becoming increasingly urgent. Based on the cold box component of the ultra-long linear infrared focal plane detector, a study was conducted on the low-temperature deformation of the focal plane, and theoretical simulation was conducted on the low-temperature deformation of the focal plane caused by multi-layer structure bonding. A test method for low temperature deformation of the focal plane of the detector at a working temperature of 90 K was designed. The results of the surface shape test were compared and analyzed with simulation calculations. The overall focal plane moved downward at low temperature, but the deformation curve was arched. The simulation showed that the chips on both sides were concave downward by about 924 m. In the middle position, the chip was concave downward by 136 m. The experimental results showed that the chips on both sides were concave downwards by about 40 m, and in the middle position, the chip was concave by 10 m. The data difference was related to the parameter setting of simulation materials. The rationality of the simulation results has been verified, which can provide a reference basis for the design of the focal plane multi-layer structure of ultra-long line array detectors.

The mesa-type InSb infrared focal plane array (IRFPA) detector typically has a simple fabrication process and high quantum efficiency. However, its filling factor is low, and it will further decrease with the reduction of the pixel size. Reducing the corrosion depth of the mesa can improve the fill factor of the detector, but it will increase the crosstalk. A novel design and preparation method for microlens arrays is introduced to improve the filling factor of InSb infrared detectors and reduce the crosstalk. Compared with the existing reflow microlens arrays, the filling rate, surface roughness, and size uniformity of this microlens array are well balanced, and it can be directly fabricated on the surface of InSb infrared detectors with a simple process. The results show that the crosstalk of the detector decreases by 26% and the optical response increases by 22%.

Flow is an important parameter in scientific research and industrial production. Vortex flowmeter is a common type in many flow measuring instruments. As fiber Bragg grating (FBG) has the characteristics of high sensitivity, small size and strong electromagnetic interference resistance, vortex flow sensing technology based on FBG is of important research significance. The sensing mechanism of FBG vortex flow is summarized, and the changes of fluid state and lift force downstream of the vortex generator are analyzed. In addition, four key problems (the vortex properties, vortex signal processing, pipeline vibration elimination and small flow measurement) under the action of the basic vortex generator are analyzed and extracted based on the research achievement. Finally, the optical suppression of interference signal, vortex flow measurement of small diameter pipeline, FBG sensing package and sensitization are summarized and looked forward to. The possible research direction in the future is also put forward, in order to develop a new vortex flowmeter.

The near infrared spectroscopy technology in the application of oil-tea camellia seed meal is taken as the research object. The modeling process of NIR spectroscopy in the detection of camellia seed meal is elaborated on the basis of a brief introduction of the principle, characteristics and analysis process of NIR spectroscopy, which provides theoretical basis and guidance for the subsequent workers to better establish the NIR analysis model of camellia seed meal. At the same time, by analyzing the development of this technology in the detection index, standard formulation and model transfer technology, three research directions of this technology (the establishment of new projects in the detection of camellia seed meal, the formulation of universally applicable standards, as well as the resolution of inter-table differences and the completion of model transfer) in the detection of camellia seed meal are summarized. Oil-tea seed meal is widely used in animal feed, special medical food, health food and other industries, so it is an inevitable trend to develop and popularize the application of near infrared spectroscopy technology in oil-tea seed meal detection.