Canon is developing wide variety of gratings that can be effective solutions for high precision spectroscopy for the next-generation ground-based and space telescopes. In this paper, we focus on our development of infrared immersion grating, which is one of the most demanding devices among various gratings. We use CdZnTe for mid-infrared (MIR) application and KRS5 for near-infrared (NIR) to MIR application. In particular, CdZnTe immersion grating is the key-device for the MIR high-resolution spectrograph for the space infrared telescope SPICA. Using our diamond cutting (planing) technique, grooves are shaped on the hypotenuse area (30 mm x 10 mm) of a CdZnTe prism with the spacing accuracy of < 5 nm (rms) and the surface roughness of < 5 nm (rms). We also performed cutting of KRS5 disk and confirmed that excellent grooves can be shaped on this material.

Date Published: 13 September 2012
PDF: 12 pages
Proc. SPIE 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II, 84502V (13 September 2012); doi: 10.1117/12.924956

Published in SPIE Proceedings Vol. 8450:
Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II
Ramón Navarro; Colin R. Cunningham; Eric Prieto, Editor(s)