Richardson Grating Laboratory of Rochester, N.Y., completed the production of three mosaic diffraction gratings for the recently constructed Subaru telescope atop Mauna Kea in Hawaii. The monolithic gratings will operate in the UV, VIS and near-IR regions of the spectrum with efficiencies of >70%. The two cross dispersers are 650 x 420 x 110 mm thick, and the echelle substrate measures 850 x 320 x 130 mm.

The 8.3-m telescope, which was constructed by the National Observatory of Japan, was designed to image objects at the limits of the observable universe.