Windows are optical glass with ground and polished faces that are relatively parallel.  They are used to isolate two physical environments while allowing light to pass. When selecting windows, you should consider the following: material, transmission, scattering, wave front distortion, parallelism and resistance to certain environment. 

VY Optics Photoelectric Technology Co.,Ltd. offers all types of windows made from different materials. Special size and materials are also available upon request. In addition, we provide a variety of single layer or multiplayer anti-reflecting coating on optical windows.
Specification of our optical windows as follow:
*Material: BK7 or other materials
*Length tolerance:+/-0.01
*Width tolerance:+/-0.01
*Center thickness tolerance:0.005mm
*Surface quality:80-50 to 10-5 Scratch/Dig
*Surface flatness:<lambda to lambda/20
*Parallelism<=1min -- 2sec
*Clear Apenture:80% -- 100%