High optical quality nanocrystalline diamond with reduced non-diamond contamination

It is important for optical applications of nanocrystalline diamond to achieve low optical absorption as well as optical scattering. We discuss the optical and photocurrent spectra measured by the transmittance and reflectance, photothermal deflection spectroscopy, laser calorimetry and dual beam photocurrent spectroscopy of low non-diamond content nanocrystalline diamond films grown by microwave plasma enhanced chemical vapor deposition on fused silica glass substrates.