laser - Is there any incoherent collimated monocromatic light source? - Physics Stack Exchange
Coherence (physics) - Wikipedia
High Harmonics Properties
Basics of coherence theory
Sivakumar Surampudi on Twitter: "Laser can also have high temporal coherence, which allows them to emit light in a narrow spectrum (a single color of light) #SundayScience https://t.co/9obfics2wX" / Twitter