Development of infrared high-dispersion grating by high precision processing

我们研制了一台用于NAOJ斯巴鲁8.2米望远镜Nasmyth焦点级的锗浸没光栅中红外低温光谱仪，工作在N波段(8-13μm)，R~50,000。采用超精密微细磨削技术，结合电解在线修整技术，制作了准直光束尺寸为φ28 mm的单晶锗浸没梯形光栅(30×30×72 mm)。该仪器已组装完成，现已用于气相红外高分辨光谱分析。

We have developed a germanium immersion grating mid-infrared cryogenic spectrograph (GIGMICS) designed for the Nasmyth focus stage of NAOJ Subaru 8.2 m telescope, which operates at N-band (8-13 μm) in wavelength with the R～50,000. A single crystal germanium immersion echelle grating (30×30×72 mm) for collimated beam size of φ28 mm was fabricated by utilizing ultra precision micro-grinding method coupled with the ELID (ELectrolytic In-process Dressing) technique. The instrument has been assembled and is now tested for the application to the gas-phase IR high-resolution spectroscopy.