| PRODUCT/SERVICES INDEX |
Calcite Crystal
Calcite, a rhombohedral crystalline form of calcite
carbonate(CaCO3), is found in various forms such as limestone
and marble. It is a negative uniaxial crystal that has high
birefringence, wide spectral transmission and availability in
reasonably sized rhombs. It is ideal material used as visible and
near IR polarizers, and also UV polarizers, such as Glan Taylor,
Glan Thompson and Glan Laser with extremely high extinction
ratio in the optics industry.
Calcite Quality
There is no generaily agreed upon set of quality specifications for
commercial calcite. Most manufacturers base their quality ratings
on U. S. military specification MIL-G-174B. There are three main
areas of importance in defining calcite quality.
Calcite, a rhombohedral crystalline form of calcite
carbonate(CaCO3), is found in various forms such as limestone
and marble. It is a negative uniaxial crystal that has high
birefringence, wide spectral transmission and availability in
reasonably sized rhombs. It is ideal material used as visible and
near IR polarizers, and also UV polarizers, such as Glan Taylor,
Glan Thompson and Glan Laser with extremely high extinction
ratio in the optics industry.
Calcite Quality
There is no generaily agreed upon set of quality specifications for
commercial calcite. Most manufacturers base their quality ratings
on U. S. military specification MIL-G-174B. There are three main
areas of importance in defining calcite quality.
1. Spectral Properties
Trace amounts of chemical impurities, as well as lattice defects, can cause calcite to be colored, which
change absorption. For visible light applications, it is essential to use colorless calcite. For near-infrared
applications, material with a trace of yellow is acceptable. This yellow coloration results in a 15% to 20%
decrease in transmission below 420nm. For UV light application, it is required to have no fluorescence at
UV light.
2. Wavefront Distortion (Striae)
Striae or Schlieren, are streaked fluctuations in the refractive index of calcite, caused by dislocations in
the crystal lattice. They can cause distortion of a light wavefront passing through the crystal, This is
particularly troublesome for interferometric applications.
3. Scatter
Small inclusions within the calcite crystal account for the main source of scatter. They may appear as
small cracks or bubbles. In general, scatter presents a significant problem only when the polarizer is used
with laser. The amount of scatter centers that can be tolerated is partially determined by beam diameter
and power.
Trace amounts of chemical impurities, as well as lattice defects, can cause calcite to be colored, which
change absorption. For visible light applications, it is essential to use colorless calcite. For near-infrared
applications, material with a trace of yellow is acceptable. This yellow coloration results in a 15% to 20%
decrease in transmission below 420nm. For UV light application, it is required to have no fluorescence at
UV light.
2. Wavefront Distortion (Striae)
Striae or Schlieren, are streaked fluctuations in the refractive index of calcite, caused by dislocations in
the crystal lattice. They can cause distortion of a light wavefront passing through the crystal, This is
particularly troublesome for interferometric applications.
3. Scatter
Small inclusions within the calcite crystal account for the main source of scatter. They may appear as
small cracks or bubbles. In general, scatter presents a significant problem only when the polarizer is used
with laser. The amount of scatter centers that can be tolerated is partially determined by beam diameter
and power.
Calcite Crystal from AD Photonics
Our raw calcite crystal are extracted from the deposit of our own to meet U.S. Military specifications
MIL-G-174B. Thanks to our unique techniques in color change, we can provide colorless calcite, which has
15~20% transmission improvement from yellow calcite at short wavelength. We may supply raw calcite on a
variety of size going from very small rhombs crystal 10mm to more than 100mm size. Our calcite grade can
be standard grade to UV grade. Please check our calcite specifications(pdf) for detail information and
calcite crystal physical and optical properties.
Our raw calcite crystal are extracted from the deposit of our own to meet U.S. Military specifications
MIL-G-174B. Thanks to our unique techniques in color change, we can provide colorless calcite, which has
15~20% transmission improvement from yellow calcite at short wavelength. We may supply raw calcite on a
variety of size going from very small rhombs crystal 10mm to more than 100mm size. Our calcite grade can
be standard grade to UV grade. Please check our calcite specifications(pdf) for detail information and
calcite crystal physical and optical properties.
| AD Photonics -- Crystals, Photonics, Optical OEM Modules Postal address: 10 Thunder Run Unit 15E, Irvine, CA 92614, USA Phone: +01-949-387-6604, Web site:http://www.adphotonics.com/ Electronic mail: Sales: sales@adphotonics.com, General information: info@adphotonics.com, Webmaster: webmaster@adphotonics.com Last modified: 12/15/02, Copyright © 2002 AD Photonics |
| Welcome to AD Photonics -- your best source for IR components, solid state lighting optics, fiber faceplates and advanced optical solutions! |
