Ring laser gyroscope

About: Ring laser gyroscope is a research topic. Over the lifetime, 2070 publications have been published within this topic receiving 18609 citations. The topic is also known as: Sagnac interferometer.

Pulsed diode ring laser gyroscope

Abstract: A pulsed diode ring laser gyroscope and method of modulation are provided to greatly reduce the occurrence of frequency locking in optical gyroscopes at low rotational rates. One or two optical diodes serve as optical amplifiers for a pair of counterpropagating optical pulses circulating in an optical ring resonator. The amplifiers are driven twice each round trip (once for each pulse) using pulses much shorter than the round trip time. The short optical pulses overlap in regions of the resonator generally isolated from light scattering elements. The pulses are produced by gain switching the optical amplifiers with an electrical current pulse train having a fundamental period synchronous with the optical round trip time in the resonator cavity. With this modulation scheme, the diodes can be thought of as gates that open twice each round trip-once for each of the counterpropagating pulses. During each on time, the diodes amplify only a clockwise or counterclockwise pulse. Backscattered light from any optical element, which is not coincident with either of the pulses, is absorbed by the amplifiers.

Sagnac effect in the colliding-pulse-mode-locked dye ring laser

Abstract: A colliding-pulse-mode-locked dye ring laser was mounted on a rotary stage and the beat frequency of the two output pulse trains was measured as a function of the rotation rate. The measurements are in good agreement with the Sagnac theory.

Ring laser gyroscopes

Abstract: A ring laser gyroscope has a primary ring 13 including a gas discharge tube 4 enclosing an active lasing medium. The gyroscope has additionally a secondary, passive ring 14 optically coupled to the primary ring 13 by a partially transmissive mirror 8. A mirror 15 of the secondary ring 14 is adjustable, under the control of a feedback loop 19, to vary the optical path length of the secondary ring 14 so that the latter resonates at one of the longitudinal modes of the primary ring 13, thereby enhancing this mode and concentrating the output power of the gyroscope in one frequency, while suppressing other longitudinal modes of the primary ring.

Winding technique for decreasing the pump power requirement of a brillouin fiber optic gyroscope

Abstract: A Brillouin fiber optic gyroscope has a cavity loop that includes a first length of optical fiber wound as a first number of turns in a first direction to provide a selected system response that includes the dynamic range of gyroscope rotation rate, the resolution of the gyroscope rotation rate measurement, the relative lock-in range and the relative Kerr-effect-induced beat-frequency bias. The cavity loop further includes a second length of optical fiber wound as a second number of turns in the same direction as the first number of turns and wound as a third number of turns in an opposite direction to the winding direction of the first and second number of turns. The effect of the second and third number of turns is to increase the overall length of the optical fiber in the cavity loop to reduce the pump power required to generate Brillouin laser light within the cavity loop without increasing the Sagnac effect within the cavity loop. Thus, the system response that includes the dynamic range of gyroscope rotation rate, the resolution of the gyroscope rotation rate measurement, the relative lock-in range and the relative Kerr-effect-induced beat-frequency bias of gyroscope rotation rate, is not substantially affected by the increased number of turns provided by the second length of optical fiber.