an apparatus, as a special table or rigid beam, for the precise positioning of light sources, screens, and optical instruments used for optical and photometric studies, having a ruled bar to which these devices can be attached and along which they can be readily adjusted.
Origin of optical bench
First recorded in 1880–85
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
an apparatus fitted for experimentation in optics, typically consisting of a table and an adjustable arrangement of light source, lenses, prisms, etc
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012