Optical device initially put together, first patented in 1960 (5)

I believe the answer is:

laser

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'optical device' is the definition.
(laser is a kind of optical device)

I don't understand how the rest of the clue works.

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(Other definitions for laser that I've seen before include "modern light industry" , "Generator of beam" , "Device that generates an intense beam of light" , "Powerful light source" , "Light amplification by stimulated emission of radiation" .)

I've seen this clue in The Guardian.

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