Light beam-splitter

US4645302A · kind A · utility

Assignee

• Crosfield Electronics Limited · GB

Inventor

• John E. Aughton · London, GB

Key dates

• Filing date: Dec 13, 1983
• Grant date: Feb 24, 1987
• Expiry date: Dec 13, 2003

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B27/145
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

To produce a plurality of parallel light beams from a single input beam, the input beam is incident on a partially transmissive face of a triangular prism, the other two faces of which are silvered. The input beam strikes the partially-transmissive face at such a position and at such an angle of incidence that it gives rise to only two parallel emitted beams, part of the emitted light arising from internal reflections at both silvered faces. A number of such prisms may be arranged in series so that the n.sup.th prism receives 2.sup.n-1 beams and emits only 2.sup.n parallel output beams. The partially-transmissive face or faces may be coated to give rise to output beams of substantially equal intensity. In one form, each beam entering each prism has equal S- and P-polarization components.