Element Six has released a single crystal CVD (Chemical Vapour Deposition) diamond suitable for demanding optical applications.
The material’s main feature is its low birefringence: with Dn of less than 10-5. The new synthetic material has been developed using proprietary processes and opens up the possibility of exploiting the excellent optical and thermal properties of diamond in a consistently engineered material without compromising other aspects of device performance.
Diamond offers a number of properties that make it unique as an optical material, and enable applications that other window materials cannot address. In particular, the material is transparent over a very wide spectrum, with very low absorption coefficients at key laser frequencies, has a very high thermal conductivity enabling any heat absorbed to be dissipated, and a low thermal expansion coefficient, limiting any thermally generated strain, which can otherwise result in beam distortion or window failure.
The new low birefringence CVD diamond has application in a range of existing and novel laser applications where the diamond is used primarily for its thermal properties, removing heat from the lasing medium, but where losses resulting from birefringence in the diamond have to date been the limiting factor. Particular applications include the development of higher power compact laser sources such as VECSELs (Vertical External Cavity Surface Emitting Lasers) where the diamond resides within the laser cavity.
This new diamond material also offers a route to increasing the range of the optical spectrum which is addressable by lasers, by working as a laser Raman medium which efficiently shifts the output frequency of a laser system.