SPIRou @ CFHT: spectrograph optical design

摘要

SPIRou is a near-infrared, echelle spectropolarimeter/velocimeter under design for the 3.6m Canada-France-HawaiiTelescope (CFHT) on Mauna Kea, Hawaii. The unique scientific capabilities and technical design features are describedin the accompanying (eight) papers at this conference. In this paper we focus on the lens design of the opticalspectrograph. The SPIROU spectrograph is a near infrared fiber fed double pass cross dispersed spectrograph. Thecryogenic spectrograph is connected with the Cassegrain unit by the two science fibers. It is also fed by the fiber comingfrom the calibration box and RV reference module of the instrument. It includes 2 off-axis parabolas (1 in double pass),an echelle grating, a train of cross disperser prisms (in double pass), a flat folding mirror, a refractive camera and adetector. This paper describes the optical design of the spectrograph unit and estimates the performances. In particular,the echelle grating options are discussed as the goal grating is not available from the market.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.