Calcite

Calcite is a negative uniaxial crystal that has high birefringence, wide spectral transmission and availability in reasonably sized rhombs. Although is a fairly soft crystal and is easily scratched, it is ideal material used as visible and Near IR polarizers, such as Glan- Taylor, Glan-Thompson and Glan-laser polarizer.

Carefully select the raw calcite crystals by inspecting them with a CW green laser beam. We have perfected a number of proprietary processes for cutting, grinding and polishing good quality optical surfaces for calcite prism. These skills are evident in the high quality of the finished components, and enable polarizer to be used with very high peak power lasers.

Basic Properties of Calcite crystals
Please view Optical Crystals Properties

Refractive Indices, Birefringence ( D n = n e - n o ) and Walk-off Angle at 45°
n o = 1.6557, n e = 1.4852, D n = -0.1705, r = 6.20° at 0.63 um
n o = 1.6379, n e = 1.4783, D n = -0.1596, r = 5.83° at 1.30 um

Sellmeier Equation ( l in um):
n o 2 = 2.69705 + 0.0192064/( l ^2 - 0.01820) - 0.0151624 l ^2
n e 2 = 2.18438 + 0.0087309/( l^ 2 - 0.01018) - 0.0024411 l ^2

Specifications of Calcite

Surface Quality	20/10 Scratch and Dig
Beam Deviation	<3 arc min.
Optical Axis Orientation	+/-0.5°
Flatness
Transmission Wavefront Distortion	< l /2 @632.8 nm
AR-coating	R<0.5%