The excellent optical properties of diamond
have been known for a long time. However, optical applications
require extended discs or thin coatings not provided by natural
diamond crystals. With the development of CVD techniques the
situation has changed completely.
Diamond is transparent from the UV (230 nm)
to the far infrared. Only minor absorption bands resulting from
two phonon absorption exist between 2.5 and 6 µm. Hence diamond
is an ideal material for multispectral optical applications.
Wide band gap
No thermal generation of charge carriers at
elevated temperatures, hence no "thermal run away" as in the
case of Germanium under laser irradiation. Furthermore, diamond
does not become nonlinear at high radiation intensities.
High thermal conductivity>
Absorbed energy is quickly dissipated to the
edges of a diamond window where it can be removed by appropriate
heat sinks and cooling techniques.
Mechanical and chemical stability
Diamond is extremely hard, wear resistant and
It is an ideal material for hostile, highly erosive atmospheres.