PS908H-A In Stock

The PS908H-A by ThorLabs is a high-quality N-BK7 right-angle prism designed to serve as a retroreflector and minimize surface reflections over a broad 350-700 nm wavelength range. With its standard antireflection (AR) coating on the hypotenuse, the PS908H-A is a reliable solution for various optical applications.

The PS908H-A is 20 mm long and allows the user to change the direction of light paths in two ways. Either a 90° or 180° angle can be achieved by choosing different sources for the light flow. When light is incident on one of the legs of a prism, it undergoes total internal reflection (TIR) at the boundary between the glass and air surfaces of the hypotenuse. This leads to a 90° shift of the input light when it exits through the other leg. As a result, the right-angle prism can serve as an effective alternative to a mirror. If the light enters the hypotenuse of the PS908H-A, it will experience TIR upon hitting the boundary of glass and air of its legs. Once it has gone through the TIR procedure again at the subsequent leg, the beam will go out of the hypotenuse in a way that is parallel to its original path. This right-angle prism has an impressive optical system, where the path of light enters and deviates 180° regardless of the angle of entry, similar to a retroreflector.