Calcite (CaCO₃), a trigonal negative uniaxial crystal with extreme birefringence and broad transmission (200 nm–2300nm), is the premier material for visible-near infrared polarizing optics despite its softness (Mohs 3) and hygroscopicity. It enables Glan–Taylor/Thompson polarizers with extinction ratios >10⁶:1, beam displacers, and UV wave plates, outperforming synthetic crystals like YVO₄ in the ultraviolet range but requiring AR coatings and humidity control.
Item No :
CalciteProduct Origin :
FuZhouSpecifications:
Dimension Tolerance:
|
+/-0.1mm
|
Optical Axis Orientation :
|
+/-0.5deg
|
Parallelism:
|
<10 arc secs
|
Perpendicularity:
|
<5 arc mins
|
Surface quality:
|
20/10
|
Flatness:
|
< λ/4 @632.8nm
|
Wavefront Distortion:
|
< λ/2 @632.8nm
|
Coating:
|
Coating upon Request
|
Properties:
Crystal Structure
|
Crystalline rhombihedralCubic
|
Density
|
2.7 g/cm3
|
Transmission Range
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350-2300nm
|
Mohs Hardness
|
3 |
Hygroscopic Susceptibility
|
Low
|
Thermal Expansion Coefficients(/C°)
|
24.39X10-6(C) ; 5.68X10-6(A) |
Refractive Indices
|
No=1.66315,Ne=1.48854, 532nm No=1.64237,Ne=1.47968, 1064nm |
Sellmeier Equation (λ in μm)
|
ne2=2.18438 + 0.0087309/(λ2-0.01018) - 0.0024411λ2 no2=2.69705 + 0.0192064/(λ2-0.01820) - 0.0151624λ2 |
Why choose Calcite (CaCO₃) Crystal?
Calcite (CaCO₃) crystal is an optical material with prominent birefringence, splitting incident light into two perpendicularly polarized beams across a transmission range from UV to mid-IR. Due to its low hardness and susceptibility to acid corrosion, protective measures are required during use. Leveraging its natural birefringence, calcite is widely used to fabricate polarization components like Nicol prisms, enabling linear polarization separation in polarizing microscopes and interferometric systems, while transparent crystals (e.g., Iceland spar) serve as optical standards or educational demonstrators.