The latest research progress of large-width, multi-band, large pixel hyperspectral infrared detectors based on molecular beam epitaxy (MBE) mercury cadmium telluride (MCT) technology is reported.High-quality MCT materials are fabricated by MBE technology. For the fabrication of the detector chips, the well-established n-on-p technology route is employed, with optimizations made for large pixels with special shapes The readout circuits, specifically designed for hyperspectral applications, have been tailored for typical characteristics such as short wavelengths, narrow spectral bands, and small signals, incorporating features like gain-selection-by-line function for spectral applications. The test results show that the basic performance of the module is good, with an operability greater than 99.5% and an average quantum efficiency greater than 70%.

In order to meet the requirement of high-precision target recognition for space-based systems, a target recognition method based on multi-band feature fusion template matching is proposed. In this paper, the multi-dimensional feature elements and classification methods of the target are firstly described and analyzed.Feature fusion processing is achieved by combining the features of the target motion, the target spectral features in multi-band and the changes of infrared radiation. Based on the changes of regional features, the dynamic wrapping template matching algorithm is adopted to complete the target identification. Finally, the parameters are trained and adjusted by combining the infrared radiation intensity sequence data of the cooperative target. The analysis results show that the proposed recognition method can realize the target model recognition well, and its performance is better than the traditional dynamic wrapping matching algorithm.

In this paper, we aim to study the transmission and evolution characteristics of femtosecond pulses in low-mode fibers. A kind of high nonlinear few-mode toluene liquid-core photonic crystal fiber (TLC-PCF) is proposed The nonlinear coefficient at the pump wavelength is about 42 W-1 . km-1. Multimode generalized nonlinear Schrodinger equation (MM-GNLSE) is used to model and solve the femtosecond pulse transmission and evolution. The energy transfer characteristics of different peak power (1 kW, 10 kW, 50 kW) are compared in this paper. When a Gaussian pulse with a central wavelength of 2000 nm, a peak power of 50 kW and a pulse width of 200 fs is transmitted in a TLC-PCF with a length of 30 cm, the supercontinuum output of 1980-2500 nm is obtained, and the energy transfer reaches the equilibrium point for the first time at 0. 02 m.The numerical results show that the energy transfer occurs in degenerate modes when a mode is excited, and it is concluded that four-wave mixing (FWM) is responsible for energy transfer between modes in TLC-PCF.In this paper, MM-GNLSE theory is innovatively adopted to analyze mode coupling, SCG and energy transfer properties in a few-mode liquid-core photonic crystal fiber with slow nonlinearity.

Geodesic laser gyro is a kind of inertial sensing device based on the Sagnac effect to measure the angular velocity of the earths rotation, which can be used in the fields of world time and geodesy. Laser gyroscopes are generally controlled by piezoelectric ceramics to shift the mirror and improve frequency stability accuracy. In view of the influence of the normal displacement of the spherical mirror on the resonator during the operation of the frequency stabilizing mechanism, starting from the definition of ring cavity stability, a more realistic ray tracing simulation, which is different from the traditional optical matrix analysis of the resonator stability, is used to analyze the influence of the normal displacement of the spherical mirror on the light output stability of the resonator. The simulation results show that the size of the ring cavity is positively correlated with the normal displacement range of the spherical mirror. The displacement range measured by experiments is about 1. 492-1. 695 mm, and the error between the experimental and simulation results is within 1%. In this paper, the influence of normal displacement of spherical mirror on geodesic laser gyro during the operation of frequency stabilizing mechanism is studied. The research results have some reference significance for the frequency stabilizing control and gyroscope construction of geodesic laser gyro.

The data variational assimilation method is based on the assumption that the observation error is untiased, so the bias correction is one of the important links in the quality control of satellite data. In this paper, the research based on ensemble learning on the bias correction of the brightness temperature of the midwave infrared channel of FY-4A/GIIRS is carried out. Random Forest, XGBoost, Decision Tree and Extra Tree are used as the base models for the ensemble learning. After optimizing the hyperparameters of the base model, the generalized error minimization method is used to integrate the base model regression results. Based on the encrypted clear-sky field-of-view data during Typhoon Lekima, the correction effects of the ensemble learning, the base model, and the offline method on the brightness temperature bias of the GIIRS channel are compared. The experimental results show that all the correction methods used in this paper achieve good results Among all the methods, the ensemble learning has the best correction effect. Among the air mass predictor, geographical (longitude and latitude) information contributes a lot to the base model. The methods in this paper can be extended to the bias or error correction of other information.

As one of the current hot technologies, optical fiber sensing technology has many important applications in the field of engineering monitoring. The application cases of optical fiber sensing technology in engineering deformation monitoring are discussed, and its importance in the field of engineering monitoring is demonstrated. Optical fiber sensing technology can realize continuous real-time monitoring of deformation and provide high-precision monitoring data by using optical fiber as the sensing element. The monitoring experiment is carried out on the K134 section viaduct of Hebijin Expressway by laying strain optical cable and temperature compensation optical cable. The results show that the optical fiber sensing technology can accurately evaluate the deformation of the structure and eliminate the influence of temperature change on the data through the temperature compensation algorithm. The settlement displacement can be estimated by geometric calculation.

The identification of gas which is easy to produce drugs plays an important role in inhibiting the circulation of drugs, but the current research on the concentration detection of gas which is easy to produce drugs is not mature. In this paper, the back propagation (BP) neural network model is established by collecting Fourier infrared spectrum information for detecting the gas mixture that is easy to produce drugs The model of BP-FTIR is verified and analyzed by taking the mixed gas experiment of ether and acetone as an example The results show that the global regression R value of the multi-component gas spectrum data collected by BP- FTIR absorption system is 0.99273, and the correlation is strong. In the mixed gas test, the maximum prediction error of ether gas is 28 ppm, and the maximum prediction error of acetone gas is 11 ppm. The overall prediction error is small, indicating that the model can predict the concentration of ether acetone mixture well.Therefore, the prediction result of concentration inversion of multi-component gas which is easy to produce drugs by neural network model is highly accurate, and this study also provides a new research idea for the de-tection of gas which is easy to produce drugs and other mixed gases