Aiming at the characteristics of large dark current of photoconductive graphene detector, based on the analysis of several dark current suppression circuits, a novel dark current suppression circuit with low temperature coefficient is designed by using the capacitive trans-impedance amplifier (CTIA) integration circuit. The simulation analysis results show that the structure has good dark current suppression capability. Compared with the traditional CTIA structure, the integral saturation time of this structure is significantly improved, and it has good integral uniformity and output linearity. In the temperature range of -20 ℃--40 ℃, the current-temperature error rate is 0.15%, and the voltage offset is less than 80 mV, which can maintain good dark current suppression function at room temperature. The detector bias voltage drift is improved by 88.7%, which provides a guarantee for the stable operation of the detector. At the same time, the suppression current is adjustable, which provides a reference for improving the non-uniformity of graphene-based detector pixels and preparing large-scale graphene-based detector arrays in the future.

The stoichiometric ratio of the surface passivation layer of mercury cadmium telluride (HgCdTe) has a crucial influence on the device performance. The influence of Ar+ sputtering energy and incident angle on the stoichiometric ratio of the surface passivation layer is simulated by SRIM software. The simulation results show that in the energy range of 300--500 eV, the nuclear stopping power of CdTe and ZnS for Ar+ is much greater than the electron stopping power, and the nuclear stopping power of ZnS is better than that of CdTe; the maximum sputtering yield of CdTe is found near the ion incident angle of 60°, and the maximum sputtering yield of ZnS is found near the incident angle of 70°; there is a preferential sputtering phenomenon in the sputtering process, and Cd and Zn elements are the preferential sputtering elements. Based on the simulation results, the quality of the passivation layer on the long-wave HgCdTe surface is significantly improved. This method establishes the relationship between the stoichiometric ratio of the passivation layer and the sputtering energy as well as the incident angle, which provides a guiding direction for the actual process. This has certain practical significance for the development of high-performance HgCdTe infrared detectors.

Various electrode plates are used in infrared module packaging, and thermal damage to their metal electrodes must be avoided during laser processing. Based on the thermal conduction analysis of thin disk samples, a concise and clear analytical expression for the steady-state temperature distribution on the sample during laser processing is obtained under reasonable assumptions. Based on this, combined with the thermal parameters of the commonly used substrate materials and electrode materials of the electrode plate, the thermal damage distance of the sapphire electrode plate with the gold electrode in the steady state is obtained to be 3.3 mm, and the average laser processing power required for samples of different thicknesses is calculated. This method is suitable for the setting of relevant parameters and the estimation of the size of the thermal damage area in the laser processing of electrode plates or chips based on different substrates and electrode materials, avoiding complex finite element simulations, and can guide the design and matching of electrode plates and the setting of laser processing parameters.

Affected by the widespread application of infrared detectors, the demand for performance data analysis of infrared detectors is diverse and complex. For some characteristic parameters that cannot be directly measured or are difficult to obtain (such as dark current, quantum efficiency, etc.), a QT-based integrated test method for infrared detector characteristic parameters is proposed, including traditional test systems and self-developed calculation software. The calculation software is developed using QT and C++ language. The underlying algorithm design and development is completed independently, so that it has the calculation function of various characteristic parameters such as the number of blackbody radiation photons, dark current, quantum efficiency, etc. at any temperature in the full band. The existing calculation software only supports a single performance parameter calculation function, and there are problems such as poor universality and low fault tolerance in the parameter calculation process. The proposed software adopts packet processing for the underlying calculation principle and integrates multiple performance parameter calculation functions. After verification by infrared detectors of various array sizes, the software has the advantages of accuracy and convenience.

Studying the infrared radiation characteristics of the side jet of an aircraft model in a wind tunnel environment and its measurement correction methods is of great significance for conducting wind tunnel tests. When measuring the infrared radiation of the side jet of an aircraft in a wind tunnel environment, the radiation generated by the inner wall of the wind tunnel and the wall of the aircraft model is an interference source for the infrared measurement of the jet. By solving the mass equation, momentum equation, energy equation and component transfer equation, the flow field of the side jet of the aircraft model in a wind tunnel environment and the infrared radiation characteristics of each radiation source in the 3－5 m band are numerically simulated. The research results show that with the increase of the Mach number Main at the inlet of the test section, the radiation intensity of the inner wall of the wind tunnel and the wall of the aircraft model increases, and the integrated radiation intensity of the side jet first decreases and then increases. By analyzing the radiation characteristics of each radiation source, the variation law of the integrated radiation intensity of each radiation source with Main is mastered, and finally the correction method of the infrared radiation characteristics of the side jet of the aircraft model in a wind tunnel environment suitable for the model of this paper and the boundary conditions is obtained.

A marine infrared target detection algorithm based on improved YOLOx-nano is proposed. By decoupling the classification and positioning tasks of the detection head and introducing an improved feature pyramid network (FPN) structure, not only the accuracy and convergence speed of the model are improved, but also the infrared large target detection capability is improved. The improved squeeze-and-excitation network (SENet) channel attention mechanism module is added to the model to enhance the nonlinear expression ability of the model and improve the effective feature learning ability. In order to speed up the forward reasoning speed of the embedded platform model, the pruning technology is introduced to implement model pruning, and the model parameters are reduced without reducing the recall rate. The algorithm in this paper is verified by the test set. The results show that the average precision (AP) of the algorithm is 1.35% higher than that of the original YOLOx-nano algorithm, reaching 93.92%. The algorithm in this paper balances the contradictory relationship between model accuracy and time consumption, and ensures the speed of model detection while improving performance.