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

The thought experiment involves putting two interferometers side by side, such that each particle first encounters a beam splitter.

From Scientific American • May 6, 2019

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

Remove the second beam splitter and interference becomes impossible.

From Science Magazine • Oct. 27, 2017

Instead, the first beam splitter sends the photon down one path or the other, like a particle.

From Science Magazine • Oct. 27, 2017