MERRIMACK, N.H., Sept. 29, 2011 — GT Crystal Systems announced it has received an order for a large, low absorption optical sapphire blank for the Large-Scale Cryogenic Gravitational Wave Telescope (LCGT) program in Japan.

The LCGT will use the sapphire optic to measure changes in gravitational waves that result from cosmic events. The extremely sensitive instrument requires sapphire containing an almost perfect crystalline structure, without bubbles or inclusions. In addition, to prevent heat from occurring, it must be very low in optical absorption.

GT Crystal Systems’ HEM sapphire has been measured to have laser absorption values lower than 40 ppm/cm at a wavelength of 1.064 µm. The blank will measure approximately 10 in. in diameter and 6 in. thick. Its delivery is scheduled for early next year.

GT Crystal Systems is a subsidiary of GT Advanced Technologies Inc., a provider of polysilicon production technology, and sapphire and silicon crystalline growth systems and materials for the solar, LED and other specialty markets.

For more information, visit: www.gtat.com