Right Angle Prism

A right angle prism is an optical prism designed to deviate light by 90° or 180°, depending on the orientation of the prism and the face through which light enters. The joining edges and faces are perpendicular to the base faces, and all joining faces are rectangular. They are often  preferable to plane mirrors, because they are easier to mount and align.  High throughput is attained when the hypotenuse is used in total  internal reflection (TIR), and the entrance and exit surfaces are  anti-reflection coated.

• inverted by 90 degrees – in the right-angle prism orientation the beam is reflected by mirror-coated hypotenuse or full internal reflection is utilized.

• inverted by 180 degrees – so called in Porro type in which the light enters via hypotenuse surface and after two internal reflections on short faces is reflected back at the direction parallel to the direction of the incident light.

• Inverted by 180 degrees and reversed – in a Dove Prism orientation the light enters in a direction parallel to hypotenuse surface, is refracted toward the hypotenuse face and after internal reflection from this surface, leaves the prism via the other leg resulting in inverted and reversed image.

The advantages of right angle prisms

The capability of right angle prism to alter the image makes it a staple component in optical systems ranging from high-performance applications in scientific, healthcare and industrial fields, as well as general use optical instruments such as telescopes or binoculars.
 
Right angle prisms offer a significant advantage compared to typical mirrors because of greater resistance to mechanical load and external stress. This makes them more suitable for applications which operate in demanding conditions, such as vibrations or rapid movements. Prisms provide also enormous improvement in terms of ease of mounting and alignment, which reduces application complexity, cost and time to market.

WISOPTIC Standard Specifications