Optical Grade Silicon:

Our partner Cimcoop and their seasoned team of engineers have over 3 decades of combined crystal growing experience. This enables our production of high-purity, Czochralski-grown silicon with very consistent quality. Our engineers understand the important balance between optical transmission and resistivity. We can control these properties to suit our customers’ specific needs.

Our custom produced silicon blanks are used as substrates for the production of IR lenses and windows operating in the 2 to 5 micron (MWIR) range.  Silicon blanks come in round, rectangular and other complex, generated geometries.  We welcome requests for any quantity from prototype orders to thousands of pieces.

Physical properties of Silicon

Melting Point 1414°C
Density 2.329 g/cm3
Thermal Expansion Coefficient 2.6 x 10-6/K
Youngs Modulus <111> 187 GPa

Material Specifications:

Diameter Up to 152 mm (6”)
Grade Optical
Purity >99.999%
Transmission from 2.5 to 5 μm (optical grade) >52%
Orientation Monocrystalline <100> & <111>, polycrystalline
Resistivity (standard Optical grade) > 20 Ohm.cm (P-type)
> 10 Ohm.cm (N-type)
Type (dopant) P – type (Boron)
N – type (Phosphorus)
Refractive index (4 μm at 25 ℃) 3.4289 and doesn’t vary more than 20 ppm over the entire blank



Si-TransmissionBlank Specifications & Tolerances

Diameter Up to 152 mm (6”)
Thickness 0.5 mm to 500 mm
Rectangles & Squares up to 152 mm (6”) long
Diameter – 0.03 mm
Thickness ± 0.02 mm
Flatness ≤10 μm
Parallelism ≤ 20 μm
Perpendicularity ≤ 20 μm
Chamfer 0.1 to 1 mm
ETV ≤ 20 μm
Roundness ≤ 20 μm


For additional information please visit  http://cimcoop.com/inproducts/3/products/1/

Information provided to our partner Cimcoop is in accordance with and under the authority of 22 CFR 125.4 (b)(2). It is authorized under Technical Assistance Agreement TA 4955-11, as amended by the U.S. Government for export only to Bulgaria for use by Naked Optics Corp (herein NOC) and Cimcoop Holding Ltd. (herein Cimcoop). It is not transferred to any unapproved party or otherwise be disposed of in any other country, either in their original form or after being incorporated into other end items without the prior written approval of the U.S. Department of State.