Prismes


Corner cubes have the property that light incident on the prism face is deflected 180 degrees regardless of its angle of incidence.

OSE-DOP

Dove prisms have the useful property of completely inverting an image by 180 degrees.
BK7 Light Pipe is an optical element for illuminating a uniform brightness distribution from a light with a non-uniform brightness distribution.

OSE-PPB

Penta prisms deflect an input beam 270 degrees regardless of the angle of incidence on the first face.
The hollow retroreflector is similar to the corner cube; it reflects the incident light back to its original source.