Optical right angle prism
Knight Optical
Right angle prisms are simply triangular blocks of glass with two 45° and one 90° angles. The precision grade right angle prisms have high surface quality and tight tolerance angles. The normal use for a RA prism is to turn light through 90° by reflection from the hypotenuse.This simple component can be supplied with a variety of coatings.The simplest is a totally uncoated right angle prism; Uncoated RA prisms will rely on total internal reflection and so is limited in the angular range it will reflect.If the hypotenuse can be coated with a standard reflecting coating, generally aluminium, which is then protected by a paint layer it will work over a wide range of incidence angles. These are commonly known as protected right angle prisms.Another option is to apply a conventional mirror surface. This allows the prism to be used as a mirror but mounted from behind. These types of prism are commonly known as external reflector prisms.For the first two options AR coatings can be applied to the input and output faces, these can be simple broadband or more effective 4 layer coatings, which help to improve the efficiency of right angle prisms.
Right angle prisms are used to bend light paths and for image displacement.
Specifications:
Material: BK7
Dimensions: ±0.1mm
Angles: ±1 arcmin
Surface quality: <40:20 scratch dig
Flatness: <λ/4 over 25mm (over inscribed eclipse)
Coating Options: See individual ranges below.
