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.

Passive type ring laser gyroscope

Abstract: PURPOSE:To prevent a zero point and a scale factor from fluctuating by a method wherein a passive type ring resonator which projects a parallel beam when the input light is a parallel beam and a drive mechanism which corrects a light emitting element in a plane vertical to an optical axis are provided. CONSTITUTION:A ring resonator 16 is composed of an optical element 16A which consists of a half mirror 161 and a mirror 162 and an optical element 16B which comprises mirrors 163 and 164. A projecting beam from the resonator 16 is made to penetrate half mirrors 18 and 19 and detected by a detector 20 and supplied to a lock-in amplifier 22 through a light detecting circuit 21. A signal of a frequency W from an oscillator 17 is supplied to the amplifier 22 and a detected light signal is synchronously detected, whereby an output can be obtained proportionally to a revolution angular speed. The positional relation of a laser rays source 11 with the half mirror 161 and a mirror group is corrected even if a temperature changes and an oscillation occurs. That is, a positional deviation is detected by a position detecting element 26, and an incident position is controlled and corrected by an X-Y fine movement mechanism 28.

Brilliouin ring laser gyroscope

Abstract: PURPOSE: To reduce variation of frequency and improve resolution by mounting a photo isolator and a phase modulator for dampening feed back component causing outside a fibering resonator and returning to the fibering resonator. CONSTITUTION: A gyro has two pump lasers 12, 14 propagating oppositely in a fibering resonator 18 and a means for coupling pump laser wave to the resonator 18. A coupler 16 for coupling pump laser supply fibers 20, 22 receiving the pump laser wave and arranged to introduce the wave to forward direction and the resonator 18 is included in the gyro. Laser light beam is coupled with the supply fibers 20, 22 for piling the laser light beam from Brillouin ring laser wave propagating oppositely in the resonator 18 and taken out to the supply fibers 20, 22 through the coupler 16 and propagated to return direction reverse from the forward direction. A waveguide path net for piling up the taken out beam includes a phase modulator 40 and carry wave is restrained and a flux is largely damped in a direction toward the resonator 18.

Inertial reference system utilizing ring laser gyro data resynchronization

Abstract: An inertial sensor assembly (ISA) (12) includes a cluster (20) of three ring laser gyros (42, 44, 46), each gyro producing an output signal having a pulse repetition rate representative of the rate of angular deviation of the ISA (12) about one of three coordinate axes X, Y, and Z. The ring laser gyros (42, 44, 46) are asynchronously dithered at a relatively constant rate. The ISA (12) also includes a triad (30) of three accelerometers (72, 74, 76), with each accelerometer producing an output signal representative of the rate of velocity deviation of the ISA (12) along one of the X, Y and Z coordinate axes. A first processor, P1 (14), accumulates the pulses produced by each ring laser gyro (42, 44, 46) over its dither period. The resultant counts are stored in registers for subsequent sampling by the P1 processor (14) at a periodic sampling rate which is greater than the dither rate. The P1 processor (14) then synchronizes each sampled pulse count to a common sampling interval, thereby eliminating errors otherwise caused by using positional data values taken at different times.

Optical Fiber Laser Gyro: Homodyne and Heterodyne Detections

Abstract: The ring interferometer with a multiturn single-mode optical fiber loop has been investigated for use as a rotation rate sensor utilizing the Sagnac effect. We have proposed an optical system with homodyne detection, in which the phase-difference bias can easily be introduced, and the rotation detection experiment was performed using the preliminary test setup with a He-Ne laser [1].

Photonic crystal based sensor or modulator

Abstract: A gyroscope having photonic crystals for sensing rotation uses the Sagnac effect to determine angular motion. The gyroscope comprises a photonic crystal capable of guiding counter-propagating light beams in a closed path. A light source, coupling, and detection apparatus permits detection of phase changes between the counter-propagating beams, thereby permitting measurement of angular rotation. The photonic crystal comprises a periodic structure of pillars and voids which creates a photonic bandgap waveguide within which light waves in the proper wavelength range propagate with low loss.