Gallium Gadolinium Garnet (Gd3Ga5O12 or GGG) single crystal is material with good optical, mechanical and thermal properties which make it promising for use in fabrication of various optical components as well as substrate material for magneto-optical films and high–temperature superconductors.It is the best substrate material for infrared optical isolator (1.3 and 1.5um), which is a very important device in optical communication. It is made of YIG or BIG film on the GGG substrate plus birefringence parts. Also GGG is an important substrate for microwave isolator and other devices. Its physical, mechanical and chemical properties are all good for the above applications. Main Applications: Large dimensions,from 2.8 to 76mm. Low optical losses (<0.1%/cm) High thermal conductivity (7.4W m-1K-1). High laser damage threshold (>1GW/cm2)