Athermalized windows from AdlOptica come in a variety of dimensions

The aThermoXX athermalized windows are cover slides for high-power industrial laser applications such as welding or melting in 3D printing. The windows have <0.1 Rayleigh length focus shift and <λ/1/4 aberration for diffraction-limited beam focusing. They come in a variety of dimensions, and have AR coatings optimized for widely used laser wavelengths and power density up to 3 kW/cm².
AdlOptica
Berlin, Germany
www.adloptica.com/athermoxx.htm