Calcite is a negative uniaxial crystal that has high birefringence, wide spectral transmission and availability in reasonably sized rhombs. Although a fairly soft crystal and easily scratched, Calcite is an ideal material for use as visible wavelengths and near IR polarizers such as Glan Taylor, Glan Thompson and Glan Laser.
We carefully select the raw Calcites 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 prisms. These skills are evident in the high quality of our finished components, and enable our Polarizers to be used with very high peak power lasers.
Transparency Range: 350nm-2300nm
Particle Shape: Crystalline Rhombihedral
Density: 2.7g/cm3
Hygroscopic Susceptibility:
Low susceptibility to moisture
Mohs Hardness: 3
Thermal Expansion Coefficient: αa=24.39 X10-6/K; ac=5.68X10-6/K
Refractive Indices, Birefringence (Δ n = ne - n0 and Walk-off Angle at 45° (ρ)
no 1.6557 ne=1.4852 Δn=-0.1705 ρ = 6.20° @0.63 μ m
ne 1.6629 ne=1.4885 Δn=-0.1744 ρ = 6.32° @1.30 μ m
Sellmeier Equation (λ in μ m)
no2=2.69705 + 0.0192064/(λ2-0.01820) - 0.0151624λ2
ne2=2.18438 + 0.0087309/(λ2-0.01018) - 0.0024411λ2
| ATTRIBUTE | COMMERCIAL | HIGH PRECISION |
| SURFACE QUALITY | 60-40 scratch and dig | 20-10 scratch and dig |
| DIMENSION TOLERANCE | ±0.1mm | ±0.05mm |
| OPTICAL AXIS ORIENTATION | ±0.5° | ±0.2° |
| FLATNESS | λ/4 | λ/10 |
| WAVEFRONT DISTORTION | λ/4 | λ/8 |
| AR COATING | R<0.2% at narrow band wavelength or Specified | |
