Development of Silicon Immersion Grating Technology for Ground-based Infrared Astronomical Spectroscopy

AST-0138235Ge， jiansilsi浸没式红外天文应用光栅，波长在1到10微米之间，将用于需要光谱分辨率在1000到10万之间的望远镜项目。将光栅浸入硅中，其红外折射率为3.4，与现在体积和质量较小的仪器相比，可以实现更高的立体角吞吐量或延展性。望远镜上的摄谱仪在观测过程中必须移动；要么在卡塞格伦（Cassegrain）或同等焦距下在天空中摇摆，要么在Nysmyth平台上旋转（以补偿曝光时旋转的视野）。大型重型仪器对低温操作提出了严峻的工程挑战。硅浸没光栅的使用将使尖端科学研究的仪器重量更轻，性能更高。第一次天文观测将在Lick 3米望远镜上进行

AST-0138235Ge, JianSilicon immersion gratings for astronomical applications in the infrared for wavelengths between 1 and 10-microns will be developed for telescope projects requiring spectral resolutions between 1,000 and 100,000. Immersing the grating in Silicon, which as an index of refraction of 3.4 in the infrared will enable much higher solid-angle throughput or etendu than is now possible for an instrument of smaller volume and mass. Spectrographs used on telescopes must be moved during the observations; either swinging through the sky at a Cassegrain or equivalent focus or rotating at a Nysmyth platform (to compensate for rotating field during exposure). Large heavy instruments present serious engineering challenges for cryogenic operation. Use of silicon immersion gratings will enable lighter-weight higher-performance instruments for cutting edge scientific research. The first astronomical observations will be on the Lick 3-meter telescope.***