| 释义 |
WordReference Random House Learner's Dictionary of American English © 2024la•ser /ˈleɪzɚ/USA pronunciation n. [countable]- Physicsa device that produces a narrow, nearly parallel, powerful beam of light by exciting atoms.
WordReference Random House Unabridged Dictionary of American English © 2024la•ser (lā′zər),USA pronunciation n. [Physics.]- Physicsa device that produces a nearly parallel, nearly monochromatic, and coherent beam of light by exciting atoms to a higher energy level and causing them to radiate their energy in phase. Also called optical maser.
- l(ightwave) a(mplification by) s(timulated) e(mission of ) r(adiation) 1955–60
Collins Concise English Dictionary © HarperCollins Publishers:: laser /ˈleɪzə/ n - a source of high-intensity optical, infrared, or ultraviolet radiation produced as a result of stimulated emission maintained within a solid, liquid, or gaseous medium. The photons involved in the emission process all have the same energy and phase so that the laser beam is monochromatic and coherent, allowing it to be brought to a fine focus
- any similar source producing a beam of any electromagnetic radiation, such as infrared or microwave radiation
Etymology: 20th Century: from light amplification by stimulated emission of radiation |