| abstract |
An optical device comprising a vanadium compensated high resistivity 6H polytype or 4H polytype SiC single crystal for transmitting light having a wavelength in the range of 420 nm to 4.5 μm. The device may comprise a window, lens, prism, or waveguide. A system comprising a source for generating light having a wavelength in the range of 420 nm to 4.5 μm and a device for receiving and transmitting said light, wherein said device comprises a vanadium compensated high resistivity 6H polytype or 4H polytype type SiC single crystal. The present disclosure also relates to crystals and methods for optical applications, the crystals comprising aluminum-doped silicon carbide crystals having residual nitrogen and boron impurities, wherein the aluminum concentration is greater than nitrogen and boron impurities The combined concentration of , and wherein the optical absorption coefficient at wavelengths from about 400 nm to about 800 nm is less than about 0.4 cm −1 . |