UV Fused Silica Right-Angle Prism

Avantier’s Silica Right Angle Prisms are crafted from UV fused silica, renowned for its minimal thermal expansion and exceptional light transmission across the UV, visible, and NIR spectral ranges. A right-angle prism is a type of optical element that has two perpendicular faces forming a right angle, and one inclined face, usually called the hypotenuse. It can be used in two different ways to deviate light:

UV Fused Silica Right-Angle Prism
UV Fused Silica Right-Angle Prism

90-Degree Deflection:

  • In this configuration, light enters one of the perpendicular faces and exits through the hypotenuse face, which is positioned at a 45-degree angle to the incident beam.
  • As the light exits through the hypotenuse, it is deviated by 90 degrees relative to its original path.
  • The image formed by this configuration is erected (upright) and reversed. This means that the image appears right-side up but is flipped horizontally.

180-Degree Deflection (Retroreflector):

  • In this configuration, the hypotenuse face is used as both the entrance and exit face for the light.
  • The main application of a right-angle prism as a retroreflector is when the plane of the incident beam includes the vertex of the prism.
  • Total internal reflection occurs at the hypotenuse face when the incident beam angle is such that the light cannot escape the prism. This results in the light being redirected back along its original path, effectively achieving a 180-degree deflection.
  • Retroreflectors are often used in various applications, such as surveying equipment, road signs, and motion capture systems, to ensure that light is reflected back towards its source.

In both cases, the right-angle prism is used to change the direction of light, with the 90-degree deflection creating an erect but reversed image, and the 180-degree deflection serving as a retroreflector for specific applications. The choice between these configurations depends on the intended use and the desired optical outcomes.

Factory Standard


UV Grade Fused Silica

Dimension Tolerance

+0.0, -0.1 mm

Clear Aperture



l/4 l @632.8 nm

Surface Quality




3 min. Deviation

1 min. Deviation

30 sec. Deviation

Size (mm)

Part Number

Part Number

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Note: Coating is available upon requirement. Protective Bevel available.

Avantier offers custom options to meet specific requirements. Our engineering team has extensive experience in designing complex optical systems for various applications.If you require more information or wish to explore the catalog of in-stock UV Fused Silica Right-Angle Prism or custom options, contact Avantier. We have a track record of over fifty years as a trusted source for custom optics.


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