GT Crystal Systems, a subsidiary of GT Advanced Technologies has obtained an order for a low absorption, huge, optical sapphire blank for the Japan-based Large-Scale Cryogenic Gravitational Wave Telescope (LCGT) program.
The sapphire optic will be used by LCGT to determine the gravitational wave changes that take place due to cosmic events. The LCGT has high-sensitivity and needs a sapphire with a nearly perfect crystalline structure. Not having inclusions or bubbles over the entire optic. The sapphire must have minimal optical absorption to ensure that there is no heat emission that may result in thermal expansion,which may cause thermal lensing. The HEM sapphire from GT Crystal Systems has very low absorption characteristics at 1.064µm wavelength. The laser absorption values of HEM sapphire is less than 40ppm/cm at this wave length.
According to the General Manager and Vice President of Sapphire Equipment and Materials Group from GT Advanced Technologies, Cheryl Diuguid, a highly pure and perfect quality of sapphire is needed for a high-end application as the LCGT
The sapphire blank will have a 10” diameter and 6” thickness. The blank will be delivered in the first part of 2012. GT’s HEM Sapphire was chosen for the LCGT program since the blank has been used in the past in other low absorption systems for instance, the Laser Interferometer Gravitational-Wave Observatory (LIGO) located in the United States.
Gravitational wave telescopes are being used by researchers to study black holes and other distant objects in the universe.
Source: http://www.gtat.com