Phody Optics Co.,Ltd. could manufacture Si Windows,Special Si Windows etc.
The details of Si Windows as follow:
Material:Silicon(Si)
Size:5mm~100mm 
Surface Quality: 40/20 scratch and dig
Surface Flatness:λ/10 ~ λ/2
Parallelism:30 arc seconds—1 arc min
Clear Aperture:>90%
Chamfer 0.25mm at 45 degree typical
Coating:AR coating or Customer design
Phody Optics Co.,Ltd is fully committed to designing and making all kinds of optical components for customer special use.