Opto Sigma

• Fused Silica - BK7, Pyrex, Zerodur™
• Borosilicate Glass for low expansion applications
• Single or double surface polish
• Super-polish minimizes subsurface damage for high power laser use
• Standard diameters from 10mm to 152.4mm

Laser components require highly polished substrates as well as high performance coatings. Scattering of laser light, or worse, laser damage can occur if the substrate is made of inferior material or if it is inadequately polished. Although our coatings may be applied to a wide variety of substrates, we offer a popular selection of laser grade optical substrates.

Ultra-Violet grade synthetic fused silica provides the best Ultra-Violet and visible transmission characteristics and is a highly durable material. It is recommended for short wavelength applications. Laser grade BK7 optical glass is the most commonly used material for laser mirrors and windows. For applications where low thermal expansion is important we offer a range of pyrex and Zerodur™ substrates also.

Our standard substrates have a laser polish on one surface and a commercial polish or ground on the back surface. We also offer “window” substrates which are laser polished on both surfaces. These should be selected for transmitting applications such as beamsplitters.

The polishing techniques we use produce a super polish with a surface roughness of 5 to 10 Angstroms and very low scatter. Material of 6 to 7 times grit diameter is removed during each grind and polish process to ensure very little sub-surface fracturing. This results in a substrate which is capable of withstanding high energy laser radiation.