Low-loss mirror

roundBK7fused silica

Excelitas low loss mirrors provide the lowest possible scattering and absorption loss making them ideal for the most demanding laser-based applications. By utilizing our proprietary state-of-the-art Ion Beam Sputtered (IBS) coating and superpolishing technology, our mirrors are manufactured to ensure the lowest possible scattering losses and deliver ultra-smooth surfaces. The micro-roughness of these mirrors is below 0.5 Å allowing them to achieve a scattering loss of under 5 ppm and a finesse of 200,000 when incorporated into optical cavities. IBS coatings deliver reflectivities of over 99.998% at any wavelength in the 450 nm to 2 μm range. These mirrors can be customized on a number of different substrate materials, including BK7, fused silica, Zerodur, ULE, sapphire and silicon. They are available in a wide range of sizes, typically 0.25 inch to 4.0 inch (6 mm to 101 mm) in diameter, with a flatness of λ/20 (at 633 nm), 10-5 surface quality over an 80% clear aperture, with zero defects (0-0) achievable over controlled sub-apertures. These mirrors are useful in any laser or laser-based system which demands extremely high reflectivity or very low loss and are typically used as cavity mirrors in low gain gas and solid state lasers, such as HeNe’s and HeCd’s, and in systems which employ nonlinear processes.