Mirror coating 2003 in Subaru Telescope

Tomio Kurakami; Masami Yutani; Tomio Kanzawa; Norio Ohshima; Saeko S. Hayashi; Tomonori Usuda; Shin-ichi Kubota

doi:10.1117/12.552291

24 September 2004 Mirror coating 2003 in Subaru Telescope

Tomio Kurakami, Masami Yutani, Tomio Kanzawa, Norio Ohshima, Saeko S. Hayashi, Tomonori Usuda, Shin-ichi Kubota

Proceedings Volume 5494, Optical Fabrication, Metrology, and Material Advancements for Telescopes; (2004) https://doi.org/10.1117/12.552291
Event: SPIE Astronomical Telescopes + Instrumentation, 2004, Glasgow, United Kingdom

Abstract

The SUBARU Telescope has four focal positions to allow different types of astronomical instrument. At present, there are four different Top Units; three types of secondary mirrors and one primary focus unit. IR secondary mirror which is one of the three units, has silver coated surface. Other secondary mirrors are coated by aluminum for observations at visible wavelength. The silver coating for IR secondary mirror was first carried out in 1999 at the medium size (1.6 m) vacuum evaporation chamber in Mitaka campus of NAOJ at Tokyo JAPAN. Since then the reflectivity had deteriorated over the years. Then, we made a plan to recoat IR secondary mirror in 2003 using the SUBARU’s large-size vacuum evaporation chamber at the summit facility on Mauna Kea, Hawaii. Some tests were performed for silver vacuum evaporation at the base facility, and then the IR secondary mirror was recoated at the summit. The reflectivity achieves 97.6% and 99.3% at the wavelength of 500 nm and 2000 nm, respectively. Degradation of the coat has not been seen 8 months after recoating. We also performed the recoating of the aluminum surface of the primary mirror in 2003. This year we made effort to simplify the procedure. The reflectivity is 91.2% and 97.4% at the wavelength of 500 nm and 2000 nm, respectively.

Citation Download Citation

Tomio Kurakami, Masami Yutani, Tomio Kanzawa, Norio Ohshima, Saeko S. Hayashi, Tomonori Usuda, and Shin-ichi Kubota "Mirror coating 2003 in Subaru Telescope", Proc. SPIE 5494, Optical Fabrication, Metrology, and Material Advancements for Telescopes, (24 September 2004); https://doi.org/10.1117/12.552291

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available