By means of total internal reflection (TIR), a right-angle prism may be used as a 90° reflector or as a 180° retroreflector. Except for reflection losses from the entry and exit faces, TIR exhibits 100% reflectivity over a very broad wavelength range. The reflecting surface should be coated with protected aluminum if the incidence angle exceeds that acceptable for TIR or if the environment does not allow the reflecting surface to be kept clean, as TIR requires.

The reflecting surface should be coated with protected aluminum if the incidence angle exceeds that acceptable for TIR or if the environment does not allow the reflecting surface to be kept clean, as TIR requires. The hypotenuse can also be used as a first surface reflector. In this case, if there is an overcoat of black paint, it should be removed with acetone.

N-BK7 is an excellent lens material for most visible and near infrared applications. It is the most common borosilicate crown optical glass, and it provides great performance at a good value. Its high homogeneity, low bubble and inclusion content, and straightforward manufacturability make it a good choice for transmissive optics.

These prisms have been tested for dangerous substances like Pb, Cd, Hg, Hex-Cr, PBB, and PBDE and have been found to be in compliance with RoHS allowable levels.