Right-angle prisms (BK7) These Right Angle Prisms are typically used for turning a beam by 90º. Uncoated Right-angle Prisms give total internal reflection of up to 100%, up to a critical angle, corresponding to 5.7º externally for BK7 (@587nm) Right-angle Prisms can also be used as an internal or front surface mirror when the hypotenuse is mirror coated, however it is important that it is kept clean. These Right-angle Prisms are available in two grades, either as Precision or Standard grade. The precision grade has flatter faces with more accurate angles. The AR Coated range achieving 99% overall efficiency with multilayer coatings for 450-900nm on entry and exit faces. The Protected range have the hypotenuse aluminised and black painted for protection (R=85% typically). The External range have the hypotenuse coated with protected aluminised for use as mirrors.

Knight Optical > Prisms > Right-angle prisms (BK7) - Precision Grade > Uncoated Only UK and EU customers are charged VAT at 17.5%, customers outside the EU and EU customers based outside the UK who have a valid EU VAT number will not be charged VAT Bulk Discounts! Where (B) appears next to a price below, bulk prices are available, click the (B) button to view! PDF Part No. Material Entry face size (mm) Price Qty Buy PTK0200 BK7 2 X 2 £23.90 PTK0500 BK7 5 X 5 £20.85 PTK0600 BK7 6.25 X 6.25 £20.85 PTK1000 BK7 10 x 10 £18.60 PTK1300 BK7 12.5 X 12.5 £23.25 PTK1500 BK7 15 X 15 £23.25 PTK2500 BK7 25 x 25 £26.50 PTK3000 BK7 30 X 30 £30.00 PTK4000 BK7 40 x 40 £41.00 PTK5000 BK7 50 X 50 £44.00 PTK6500 BK7 65 X 65 £48.50 Knight Optical > Prisms > Right-angle prisms (BK7) - Precision Grade > Uncoated

Specification for precision grade Material: BK7 Material data: (see materials section) Dimensions: ±0.1mm Angles: ±1 arcmin Surface quality: <40:20 Flatness: <λ/4 over 25mm (over inscribed eclipse) Coating:   Protected type: Protected aluminium / Visible use (see MV02 coating spec) External type: Protected aluminium / Visible use (see MV02 coating spec) AR coated type: Extended broadband multilayer AR / visible & IR use (see AR06 coating spec)

Note Squares & Rectangles have clean cut and chamfered edges. Diameters have fine ground and chamfered edges Specific requirements We can manufacture Right angle prisms to any size at short notice so if your requirements are not listed please contact us by telephone / fax or email: stockrequirement@knightoptical.co.uk Options available   · Thickness dimension can be machined to a smaller size at sort notice. See also Porro prisms (inverting prisms section)