Immersion grating mount design for IGRINS and GMTNIRS

摘要

The IGRINS (Immersion GRating INfrared Spectrometer) is a high resolution wide-band infrared spectrographdeveloped by the Korea Astronomy and Space Science Institute (KASI) and the University of Texas at Austin (UT).Immersion grating is a key component of IGRINS, which disperses the input ray by using a silicon material with alithography technology. Optomechanical mount for the immersion grating is important to keep the high spectralresolution and the optical alignment in a cold temperature of 130±0.06K. The optical performance of immersion gratingcan maintain within the de-center tolerance of ±0.05mm and the tip-tilt tolerance of ±1.5arcmin.The mount mechanism utilizes the flexure and the semikinematic support design to satisfy the requirement and theoperation condition. When the IGRINS system is cooled down to a cold temperature, three flexures compensate for thethermal contraction stress due to the different material between the immersion grating and the mounting part (aluminum6061). They also support the immersion grating by an appropriate preload. Thermal stability is controlled by a copperstrap with proper dimensions and a heater. Typically, structural and thermal analysis was performed to confirm themount mechanism. This mechanism will be also applied to the GMTNIRS (Giant Magellan Telescope Near InfraRedSpectrograph) instrument, which is a first-generation candidate of the GMT telescope.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.