optical resonator; optical cavity
Technical term in optics and laser physics; refers to a structure that confines light by resonant recirculation.
An optical resonator is essential for laser oscillation.
Adjust the mirror spacing of the optical cavity to change the resonant frequency.
Compound of 光 (こう, 'light') + 共振器 (きょうしんき, 'resonator'). A straightforward technical calque from English 'optical resonator'.