Performance of infrared detectors applied in astronomical telescopes

Abstract

This paper describes the significance of infrared astronomy and the development of infrared detectors for astronomical telescope applications. First, the requirements of astronomical observations on infrared focal plane detector indicators such as dark current, readout noise, and image element size are analyzed, and the infrared detector performance parameters of major domestic and foreign astronomical telescopes in recent decades are summarized. Compared with foreign countries, the performance of domestic infrared astronomical telescopes, especially dedicated astronomical infrared detectors, is still very backward. For example, the readout noise is two orders of magnitude higher than the Webb telescope's 5.9e-, and the dark current is four orders of magnitude higher than the Webb telescope's 0.001e− / <i>pixel</i>∙s. Based on the NIR spectroscopic observation requirements of the 1-meter infrared solar telescope at Yunnan Observatory, we developed a low dark current and low noise 640×512 InGaAs NIR focal plane detector module and a dedicated imaging circuit for sunspot imaging and spectroscopic testing. Measurements using the photon curve transfer method showed that the dark current of the InGaAs NIR focal plane camera was as low as 64<i>e</i>⁻/ <i>pixel</i>∙s, and the average readout noise of the image elements was 25.4<i>e</i>⁻.Finally, the research direction of special infrared detectors for astronomical observation is discussed, and this paper has implications for the research of next-generation astronomical infrared telescopes in China.