Transparent dielectric block combining two beams - is angled so that one beam is reflected in same direction as emergent path of other beam

摘要

The superimposing of two different polarised or unpolarised beams (1, 2) of electromagnetic radiation is effected by using the reflection characteristics of a transparent dielectric block (3) in the beam path. One of the beams (1) with its oscillation plane parallel to the incident plane strikes the dielectric block (3) at the Brewster angle, so that it passes through the surface of the block (3) without reflection. The other beam (2) has an oscillation plane perpendicular to the incident plane and strikes the block (3) at an angle such that it is reflected in the same direction, as the emergent path of the first beam (1). The block (3) can be used to combine two laser beams used for comparative measurement.