Infrared techonlogy and application
2022, 51(1): 20210987.
doi: 10.3788/IRLA20210987
Polarization imaging is a new way for photoelectric detection, which provides more one-dimensional information than conventional imaging systems. It has important application in the fields of industrial detection, biomedicine, earth remote sensing, modern military, aerospace and ocean. The typical applications, development history and status of polarization imaging were firstly analyzed and summarized. Then, the current methods of polarization imaging were reviewed. The latest research of polarization characteristics, transmission property, polarization imaging sensors, nonuniformity correction for division-of-focal-plane polarimeters, super resolution restoration for polarization image, and polarization information fusion approaches were introduced. Moreover, the future development direction of polarization imaging was prospected, which including focal plane polarization detector with high extinction ratio, division-of-focal-plane multispectral polarization detector, non-uniformity correction method with high precision, polarization image super resolution restoration method, and polarization information fusion(intensity image, degree of polarization and angle of polarization) so on.
2020, 49(10): 20190525.
doi: 10.3788/IRLA20190525
In order to realize the high performance detection of CO2 gas isotope, a multi-pass gas cell temperature and pressure control system with high precision and stability was developed in this paper. Flexible PCB was used as heating sheet to cover the cylindrical multi-pass cell. Considering the heating rate of the temperature control system, the outer coating of thermal insulation cotton served as the heat insulation device, which enabled the whole temperature control system to achieve rapid heating and keep the temperature stable for a long time. Platinum resistance PT1000 temperature sensor was utilized to accurately collect the multi-pass gas cell temperature. The main controller regulated the heating power of the flexible PCB heating film through PWM signal, so as to realize the closed loop of temperature control. In terms of pressure control system, the pressure sensor was connected to the front and back end of the multi-pass gas cell to measure the inside pressure of multi-pass gas cell. The main controller regulated the proportional valves that were at the front and back end of the multi-pass gas cell via PWM signal, so as to realize the closed loop of pressure control. The results show that the temperature control range is from 18.48 ℃ to 42 ℃, and the temperature control precision is ±0.08 ℃. When the pressure of the multi-pass gas cell is 60 Torr (1 Torr ≈ 133.322 Pa), the control accuracy is ±0.04 Torr. The system provides reliable guarantee for the high performance measurement of infrared CO2 gas isotope.
