Oral Presentation
Design of near infrared camera based on HgCdTe detector cooled to 80K by Stirling refrigerator
Presenter: Wenqing Qu (中国科学技术大学)
The infrared astronomy is a very important branch of astronomy, and imaging observation is the basic approach to conduct infrared astronomy observation. Therefore, it is very important to observe the J, H, K band near-infrared detectors of the atmospheric window at 1um -2.5um band on the ground. HgCdTe material has a significant impact on the development of infrared detection technology, because it is an ideal material for preparing avalanche photodiodes with high gain, high sensitivity and high-speed detection. As a result, using the HgCdTe detector to meet the needs of infrared astronomical observation is an excellent solution.
To meet the design requirements of low noise and high pixel readout rate, it is necessary to optimize the design of the readout circuit and suppress power noise. Additionally, reducing the dependence on telescope observation can be achieved by scaling down electronic devices and minimizing power consumption.
For infrared astronomical observation, the key parameters are dark current and readout noise, because astronomical observation requires a long time integration to obtain weak signal detection. In order to achieve low dark current and low infrared background radiation, we use Dewar to maintain the detector in a vacuum environment, and use Stirling refrigerator to reduce the operating temperature of the detector Dewar to 80K. The performance of the finally realized infrared observation camera can achieve dark current less than 20 e- and noise less than 50 e-。The camera can meet the observation requirements of 1.5um - 1.8um infrared band for astronomy.
asiaa.sinica.edu.tw