Dichroic Mirrors are coated with high reflecting at one wavelength and high transmission at another wavelength. Kinds of material, size with dichroic coating are available from MT-Optics,Inc.

Specifications:

Material:--------------------------- -N-BK7, UV Fused silica etc.

Typical Diameter (Фmm):------ 10.0, 12.7, 15.0, 20.0, 25.4, 30.0, 50.8, etc. 
Diameter Tolerance: ----------- +/ -0.1mm 
Thickness Tolerance: -------- ±0.2mm 
Clear Aperture: ------------------->80% 
Parallelism: ---------------------- 3'(Standard), 1’(High Precision)  
Surface Quality: ----------------- 60/40(Standard), 10/5(High Precision) 
Flatness( per 25mm @633mm): ----------λ/4((Standard), λ/8(High Precision)
Bevel: ------------------------------ <0.25mm x 45deg
Coating: -------------------------- HR@wavelength-1+HT@wavelength-2 on one side and AR @wavelength-2 on the other side with AOI=0deg or 45deg

Coating Examples: