Laser Polarising Cube Beamsplitters
These
thin film stacks, deposited on the internal surface of a cube beamsplitter are
effective polarisers for laser applications.
The coatings are designed to provide almost total reflection of the
s-component and a very high transmission of the p-component.
They are narrow-band devices operating best at the laser wavelength and a
narrow region around it. A useful
extinction ratio 1000:1 is obtained using BK7 glass prisms, cemented together.
This form is suitable for laser of fluence up to 1J/cm2
(10ns).
For
use with high power lasers, either BK7 or UV Fused Silica prisms are optically
contacted. This reduces the
extinction ratio to 200:1 but increases the laser damage threshold to 10J/cm2
(10ns).
These
beamsplitters are usually supplied as 5, 10, 15 or 20 mm cubes but other sizes
can be supplied on request.
Most
common laser wavelengths are available.