Broad transparent spectral range 0.2μm to 2.5μm
High birefringence
Soft and easy to be scratched
Applications: Polarizers, Beam divergent element, time delay compensation.
Calcite crystal is a negative uniaxial crystal well-known for its high birefringence and transparence in broad region of spectrum. It is the ideal material for manufacturing various polarizers used in visible-IR range such as Glan-Taylor polarizers, Glan-Thompson polarizers and Glan laser polarizers. Recently, calcite plate is also widely used for time delay compensation between two orthogonally polarized ultrafast pulses.
Basic Properties
| Crystal Structure | Crystalline rhombihedral |
| Density | 2.7 g/cm3 |
| Mohs Hardness | 3 |
| Hygroscopic Susceptibility | Low |
| Transparency Range | 350-2300 nm |
| Thermal Expansion Coefficients | aa=24.39x10-6/K |
| ac=5.68x10-6/K | |
| Crystal Class | Negative uniaxial with no=na=nb, ne=nc |
| Refractive Index | no=1.6557, ne=1.4852@633nm |
| Birefringence (Δn=ne-no) | Δn = -0.1705@633nm |
| Walk-Off Angle at 45 deg(ρ) | ρ=6.32@633nm |
| Sellmeier Equations (λ in um) | no2=2.69705+0.0192064/( λ2-0.01820)-0.0151624λ2 |
| ne2=2.18438+0.0087309/( λ2-0.01018)-0.0024411λ2 |
| Size | Up to Φ30mmx30mm |
| Surface Quality | 10/5 to MIL-PRF-13830B |
| Flatness | λ/4 @633 nm |
| Optical Axis Orientation | 6 arc min |
| Parallelism | 20 arc sec |
| Clear Aperture | > 90% |
| Coating | AR-coating or P-coating |
| Mount | Upon Customer's Specification |