Optical Grade CVD Single Crystal Diamond Wafer

What is CVD diamond. 

CVD diamond (also known as Synthetic diamond, Chemical vapor deposition diamond,  laboratory gown diamond, laboratory - created diamond ) is diamond produced in an artificial process, as opposed to natural diamonds, which are created by geological processes. 

There are several methods used to produce synthetic diamond.
The original method uses high pressure and high temperature (HPHT) and is still widely used because of its relatively low cost. 
The process involves large presses that can weigh hundreds of tons to produce a pressure of 5 GPa at 1500 °C.
The second method, using chemical vapor deposition (CVD), creates a carbon plasma over a substrate onto which the carbon atoms deposit to form diamond.

The advantages of CVD diamond growth include the ability to grow diamond over large areas and on various substrates, and the fine control over the chemical impurities and thus properties of the diamond produced. Unlike HPHT, CVD process does not require high pressures, as the growth typically occurs at pressures under 27 kPa