Silver coating of the Subaru telescope IR secondary mirror

We describe the silver coating of 1.3-m secondary nirror being used for infrared observations at Subaru Telescope. This was the first successful in-house runof silve coating on thelarge moern astronimical mirror. Silver was desposited over the chromium bondange layer, using a 1.6-m vacuum coating chamber at the Advanced technology Center of the National Astronomical Obervatoryof Japan in March 1998. The reflectnc eand scatter performnce are measured by micrScan at 670 nm and 1300 nm. Monitor over 17 month shows the silve coated mirror continues to maintain high refleciton.