Noun
coherent light (uncountable)
(physics) Light of a uniform wavelength and phase; as used in lasers
Subjective speckles When an image is formed of a rough surface which is illuminated by a coherent light (e.g. a laser beam), a speckle pattern is observed in the image plane; this is called a “subjective speckle pattern” – see image above. Source: Internet
In 1919, Schrödinger performed his last physical experiment on coherent light and subsequently focused on theoretical studies. Source: Internet