beam splitter

American  

noun

Optics, Photography.

1. a mirror or prism that divides a beam of light into two parts by reflecting a part of the beam, used in camera range finders.

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beam splitter British  

noun

1. a system that divides a beam of light, electrons, etc, into two or more paths

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Etymology

Origin of beam splitter

First recorded in 1930–35

Example Sentences

The first splits a laser beam in two by directing it through a beam splitter to both ends of the scale, where they are reflected by attached mirrors.

From Scientific American • Apr. 29, 2023

Again, the delayed decision seems to reach back in time, defining how the photon behaved after it left the first beam splitter.

From Science Magazine • Oct. 27, 2017

As the paths cross where the second beam splitter would have been, the detectors click with equal probabilities regardless of the paths’ lengths.

From Science Magazine • Oct. 27, 2017

The beams reflect off mirrors and race back to the beam splitter.

From Science Magazine • Aug. 4, 2016

Physicists using an interferometer, an experimental device that includes the beam splitter, toggled between combining the paths and leaving them separate.

From Scientific American • Nov. 6, 2012