Optical Isolators
These
optical isolators consist of a polarising beamsplitter cube to which a quartz
quarter waveplate has been cemented. Light
transmitted by the beamsplitter is p-polarised and then converted by the
waveplate to circularly polarised. Any
return beam is converted to s-polarized light by the waveplate and rejected by
the splitter. This type of isolator
is ideal for free-space use in a laser system.
It is easy to mount and requires no complex setup.
Optical
isolators are narrow-band devices operating best at the laser wavelength and a
narrow region around it. They are anti-reflection coated for the laser
wavelength of interest. Isolation
of the return beam is at least 30dB and transmittance of the p-component is
about 95%.
These
isolators are only suitable for lasers of fluence up to 1J/cm2 (10ns)
due to the cement interface. Optically
contacted isolators should be requested for use with high power lasers.
Most
visible and near infra-red laser types can be accommodated including the
following wavelengths: 442, 488, 515, 527, 532, 633, 670, 680, 694, 780, 830,
905, 1047, 1053, 1064, 1310, 1319, 1540, 1550 nm.
Optical
isolators may are supplied as 10, 12.7, 20 or 25.4 mm cubes but other sizes can
be supplied on request.