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

AST-0138235Ge，JianSilicon浸没光栅用于红外天文应用，波长在1到10微米之间，将为要求光谱分辨率在1,000到100,000之间的望远镜项目开发。将光栅浸入硅中，硅在红外中的折射率为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etendu。望远镜上使用的光谱仪必须在观测过程中移动；要么以卡塞格伦或同等焦距在天空中摆动，要么在尼史密斯平台上旋转(以补偿曝光期间的旋转场)。大型重型仪器对低温运行提出了严峻的工程挑战。硅浸没光栅的使用将使更轻、更高性能的仪器能够用于尖端科学研究。首次天文观测将在Lick3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.***