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Knight Optical(UK) Ltd - [email protected] - +44 (0)1622 859444

Precision right-angle prisms (BK7 or equivalent )

What are you looking for in Stock?

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 right-angle prism is to turn light through 90° by internal reflection from the hypotenuse. These right angle prisms are stocked with a variety of coatings to meet a variety of applications. The simplest is a totally uncoated right angle prism; uncoated right-angle prisms will rely on total internal reflection and so is limited in the angular range it will reflect. Prisms coated with a standard reflecting coating, generally aluminium, will work over a wider range of incidence angles. 

These are commonly known as protected right angle prisms. Another option is to apply a conventional mirror coating on the hypotenuse surface, which allows the prism to be used as a mirror but mounted from behind, these types of prism are commonly known as external reflector prisms. We also supply a stock range of extended broad band anti-reflective right angle prisms coated on the input and output faces to improve efficiency. Right angle prisms are generally used to bend light, reflect light and for image displacement.

Stock right angled prisms are available to purchase directly from this site. We also offer custom right angled prisms in unique sizes and designs to meet our customers individual requirements. For more information on our custom capabilities or to place an order, please contact our technical sales team.

Material: N-BK7 or equivalent
Dimensions: +0.0/-0.2mm
Angles: ±1 arcmin
Surface quality: <40:20 scratch dig
Flatness: <λ/4 over 25mm (over inscribed eclipse)

AR coated range:
Antireflective coated/ extended visible (AV2)
Broadband Multilayer AR, R.avg<0.5%@450-950nm, AOI= 0°-45 °
Protected range:
Protected aluminium/ visible use (MV2) Ali/SiO₂ R.avg.>88%@450-650nm,AOI=0°-45°
Protection is matt black paint however surfaces on custom prisms can be coated with epoxy matt black paint, see docs and drgs tab
External reflector range:
Protected aluminium/ visible use (MV2)
Ali/SiO₂ R.avg.>88%@450-650nm,AOI=0°-45°

Options listed here for right angle prisms:

  • Uncoated range: All faces are left uncoated.
  • AR coated range: Antireflective coating on entry/exit faces to achieve 99% efficiency.
  • Protected range: Aluminised and black painted on Hypotenuse to achieve 90% internal reflection over a greater angular range.
  • External reflector range: Aluminised and protected on hypotenuse for use as mirrors.
  • Uncoated prisms can be coated with a range of mirror coatings for UV,NIR and FIR applications.
  • Prisms can be ground down on width to smaller dimensions.
  • Prisms can be reshaped to meet your instrument needs.

Paint epoxy matt black PAT-EC75

AR coatings: 
Antireflective coated/ extended visible (AV2)
Broadband Multilayer AR, R.avg<0.5%@450-950nm, AOI= 0°-45 °
Mirror coatings: 
Protected aluminium/ visible use (MV2) Ali/SiO₂ R.avg.>88%@450-650nm,AOI=0°-45°
Protection is matt black paint however surfaces on custom prisms can be coated with epoxy matt black paint, see docs and drgs tab

Stock Optics

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Part No. CoatingGradeEntry Face Height A/C
Entry Face Height B/C
Material Price
PTK0200 UncoatedPrecision22N-BK7 or equivalent £24.95
PTK0201 AR coated (Entry exit faces)Precision22N-BK7 or equivalent £34.95
PTK0202 ProtectedPrecision22N-BK7 or equivalent £31.95
PTK0203 External reflectorPrecision22N-BK7 or equivalent £31.95
PTK0500 UncoatedPrecision55N-BK7 or equivalent £24.95
PTK0501 AR coated (Entry exit faces)Precision55N-BK7 or equivalent £34.95
PTK0502 ProtectedPrecision55N-BK7 or equivalent £31.95
PTK0503 External reflectorPrecision55N-BK7 or equivalent £31.95
PTK0600 UncoatedPrecision6.256.25N-BK7 or equivalent £26.95
PTK0601 AR coated (Entry exit faces)Precision6.256.25N-BK7 or equivalent £36.95
PTK0602 ProtectedPrecision6.256.25N-BK7 or equivalent £33.95
PTK0603 External reflectorPrecision6.256.25N-BK7 or equivalent £33.95
PTK1000 UncoatedPrecision1010N-BK7 or equivalent £28.45
PTK1001 AR coated (Entry exit faces)Precision1010N-BK7 or equivalent £38.45
PTK1002 ProtectedPrecision1010N-BK7 or equivalent £34.45
PTK1003 External reflectorPrecision1010N-BK7 or equivalent £34.45
PTK1300 UncoatedPrecision12.512.5N-BK7 or equivalent £30.45
PTK1301 AR coated (Entry exit faces)Precision12.512.5N-BK7 or equivalent £40.45
PTK1302 ProtectedPrecision12.512.5N-BK7 or equivalent £37.45
PTK1303 External reflectorPrecision12.512.5N-BK7 or equivalent £37.45
PTK1500 UncoatedPrecision1515N-BK7 or equivalent £33.95
PTK1501 AR coated (Entry exit faces)Precision1515N-BK7 or equivalent £43.95
PTK1502 ProtectedPrecision1515N-BK7 or equivalent £40.95
PTK1503 External reflectorPrecision1515N-BK7 or equivalent £40.95
PTK2500 UncoatedPrecision2525N-BK7 or equivalent £37.45
PTK2501 AR coated (Entry exit faces)Precision2525N-BK7 or equivalent £47.45
PTK2502 ProtectedPrecision2525N-BK7 or equivalent £44.45
PTK2503 External reflectorPrecision2525N-BK7 or equivalent £44.45
PTK3000 UncoatedPrecision3030N-BK7 or equivalent £49.45
PTK3001 AR coated (Entry exit faces)Precision3030N-BK7 or equivalent £59.45
PTK3002 ProtectedPrecision3030N-BK7 or equivalent £56.45
PTK3003 External reflectorPrecision3030N-BK7 or equivalent £56.45
PTK4000 UncoatedPrecision4040N-BK7 or equivalent £75.95
PTK4001 AR coated (Entry exit faces)Precision4040N-BK7 or equivalent £85.95
PTK4002 ProtectedPrecision4040N-BK7 or equivalent £82.95
PTK4003 External reflectorPrecision4040N-BK7 or equivalent £82.95
PTK5000 UncoatedPrecision5050N-BK7 or equivalent £99.95
PTK5001 AR coated (Entry exit faces)Precision5050N-BK7 or equivalent £109.95
PTK5002 ProtectedPrecision5050N-BK7 or equivalent £106.95
PTK5003 External reflectorPrecision5050N-BK7 or equivalent £106.95
PTK6500 UncoatedPrecision6565N-BK7 or equivalent £124.95
PTK6501 AR coated (Entry exit faces)Precision6565N-BK7 or equivalent £134.95
PTK6502 ProtectedPrecision6565N-BK7 or equivalent £131.95
PTK6503 External reflectorPrecision6565N-BK7 or equivalent £131.95

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Get in touch

Our Multi-Lingual Sales Team are here to help with your requirments:

UK +44 (0)1622 859444
UK +44 (0)1622 850614
UK +44 (0)1622 851078
+1 401 583 7846

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