Back Laserkreisel German Giróscopo láser de anillo Spanish Gyrolaser French RLG HE Giroskop laser cincin ID Giroscopio ottico Italian リングレーザージャイロスコープ Japanese 링 레이저 자이로스코프 Korean Ringlasergyrokompas Dutch Żyroskop laserowy Polish
A ring laser gyroscope (RLG) consists of a ring laser having two independent counter-propagating resonant modes over the same path; the difference in phase is used to detect rotation. It operates on the principle of the Sagnac effect which shifts the nulls of the internal standing wave pattern in response to angular rotation. Interference between the counter-propagating beams, observed externally, results in motion of the standing wave pattern, and thus indicates rotation.