Optical properties of CVD-diamond in terahertz range and its applications on the NovoFEL

The optical properties of a CVD-diamond in the terahertz range were studied by three different independent methods. A very stable universal gas laser was used to measure precisely the CVD transmittance. A method of vacuum Fourier spectroscopy was applied to investigate the frequency dependencies. The absorption coefficient of the CVD-diamond was determined directly by a calorimetric method on the Novosibirsk terahertz free electron laser.