Porro Prisms operate on the priciple of total internal reflection (TIR). A beam entering perpendicular to the entrance / exit surface is reflected by the two roof surfaces and emerges parallel to itself. For applications in which either the acceptance angle for TIR is exceeded, or the reflecting surfaces cannot be kept sufficiently clean for TIR, a metal or dielectric coating can be applied to the reflecting surfaces.

TO ORDER : Specify part number as follows: Substrate Code + Coating Code 

Example: BK7; 10.0mm diameter; 5 arc sec; 488 nm; Narrowband AR on entrace / exit 

surface; Protected Aluminum on reflecting surfaces: PP 1005 K 048 NA PA 

Other substrate materials, specifications, coatings and wavelengths can be provided upon request. 

Please contact our sales department for assistance.