Title: VPH grisms for the Subaru Telescope

Authors: Noboru Ebizuka, Shuji Sato, Kaoru Nakajima, Keiko Oka, Akiko Yamada, Masako Kashiwagi, Kashiko Kodate, Kohtaro Ichiyama, Takashi Ichikawa, Chihiro Tohkoku, Toru Yamada, Masakazu Harashima, Tsutomu Okura, Koji Kawabata, Kazuhiro Shimasaku, Takashi Hattori, Nobunari Kashikawa, Masanori Iye

Abstract:
A VPH (volume phase holographic) grating achieves very high diffraction efficiency nearly 100 % at the peek. A VPH grism consists of a VPH grating sandwiched between two prisms. We use a hologram resin supplied by Nippon Paint Co. Ltd. for VPH grating. We have developed three high dispersion grisms (R~3,000) and three ultra-high dispersion grisms with zinc selenide (ZnSe) prisms (R~7,500) of FOCAS, and three pair of grisms with ZnSe prisms (R~3,000) of MOIRCS. R-z band medium dispersion grism (R~1,700) and z-Y band high dispersion grism of FOCAS, and K band grism (R~2,500) of MOIRCS are under development.