It has three mutually perpendicular surfaces and a hypotenuse face. Light entering through the hypotenuse is reflected by each of the three surfaces in turn and will emerge through the hypotenuse face parallel to the entering beam regardless of the orientation the incident beam. It is often used to the distance measurement, optical signal process and laser interferometer.
|Angle Tolerance||30 arc second|
|Surface Figure||1/4 wave @632.8nm|
|Surface Quality||10-5 scratch and dig|
|Coating||None, AR, AL...|