Europe, UK, Asia & RoW: [email protected] +44 (0)1622 859444 | USA & Canada: [email protected] +1 401-583-7846


Looking For a Custom Optical Solution? Enquire

Littrow Prisms

Knight Optical supply custom Littrow prisms that cover the visual and NIR range.

Littrow prisms: The littrow prism is, usually, a 30°-60°-90° prism that can be used as a dispersive, deviating, or retro-reflecting brewster prism. The uncoated littrow prism can be used to disperse light from a source, such as a white light, into its constituent components (its spectrum). With the base surface, the long surface that has a 90° angle with the shortest surface and a 30° angle with the hypotenuse, coated with a reflective coat, such as aluminium, the input beam is deviated by 60°. The beam enters the shortest face surface to be reflected from the hypotenuse to the base surface. At this point, if the base is not coated, it is refracted out to form the spectrum of the input beam. With the base surface coated the beam is reflected and exits from the hypotenuse surface at an angle of 60°. The image, in this case, is not inverted or reverted.

In the retro-reflecting brewster configuration, the hypotenuse of the littrow prism is coated with aluminium, or other reflecting material. The laser beam enters the base surface at the brewster angle and is refracted to the hypotenuse at normal incidence where it is reflected. This beam is further refracted by the base surface and the beam travels back to the laser. As the laser beam is refracted upon entry to the prism, the spectrum of the laser is spread out such that the correct wavelength for the laser can be retro-reflected to the cavity for maximum efficiency. By rotating the littrow prism it is possible to tune the laser.

Knight Optical supply high quality custom littrow prisms made to your custom specification. Every component is individually tested by our highly skilled technicians in our state of art metrology lab to ensure all components meet our high quality standards.

Contact our multilingual technical sales team and discover how Knight Optical’s high quality custom littrow prisms and service can improve your instrumentation and supply chain experience.

Our 2022/2023 Catalogue

Inside Knight Optical’s catalogue you’ll find details of the industries we serve as well as the many other services we can offer. It also showcases hundreds of our most popular products, supported by useful technical information, to help you choose the right part for your application.
Click below to view our digital catalogue now.

view our catalogue