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.

Progress toward a compact solid state active laser gyroscope

Abstract: The two counter-propagating waves in a mode-locked ring laser--as opposed to a cw ring laser--can be totally uncoupled in phase. As a result, these lasers can be used as ultra-sensitive detectors of phase shifts, and in particular, laser gyros. Some of the implementations of these laser gyros are reviewed.

Fibre optic sagnac interferometer for rotation rate measurement with wavelength-stabilised light source

Abstract: The subject-matter of the invention is the additional use of an integrated optical chip (MIOC) as a Michelson interferometer for stabilising the wavelength of a light source (L) within a fibre-optic Sagnac interferometer for rotation rate measurement, in which a phase modulator contained in the integrated optical chip is acted on both via a digital phase ramp (AT1) dependent on the rotation rate for resetting, and by a statically independent second signal component which optimises the working point of the phase modulator (PM). With this kind of statically independent alteration of the phase modulation, the measurement signal of the Michelson interferometer, dependent on the light wavelength, can be demodulated from the detector read-out signal and can be used for readjusting the light-source wavelength by means of light-source temperature alteration and/or injection-current alteration for the light source (L). In open-loop operation, changes in the scale factor can be compensated for from the measurement signal dependent on the light wavelength.

Extended laser life

Abstract: Extended laser life may be obtained by measuring, with an ammeter AM, the discharge current applied to a laser (either linear or a ring laser gyro RLG), measuring the intensity of the resulting light beam with an intensity monitor IM, calculating the noise with an integrated circuit IC, and maintaining the discharge current at the lowest level possible which is consistent both with maintaining the intensity above the intensity service limit and the noise below the noise service limit.

Adaptive tracking dithering control system for digital laser gyro and implementation method of adaptive tracking dithering control system

Abstract: The invention provides an adaptive tracking dithering control system for a digital laser gyro and an implementation method of the adaptive tracking dithering control system. The system comprises an all-digital phase-locked loop, a noise-adding circuit, a PWM pulse width modulation driving circuit, a resonant cavity, a dithering wheel or a dithering rod and a dither signal detecting circuit. The dithering control method comprises the steps that the center frequency of the phase-locked loop is adjusted to be consistent with the natural frequency, pre-measured at normal temperature, of the resonant cavity; after phase-locked loop output signal noise adding and PWM modulation are performed, the dithering wheel or the dithering rod is loaded with the driving circuit, so that the resonant cavityis in a resonant state, and a resonant cavity dither signal is demodulated from beat note signals output from the laser gyro as an input signal of the phase-locked loop to form a closed-loop system.Due to the ambient temperature, aging of the resonant cavity and the like, the natural frequency of the resonant cavity changes, the phase-locked loop in the closed-loop system can adaptively track the input signal frequency, so that the frequency of a driving signal is consistent with the natural frequency of the resonant cavity, and the resonant cavity is in a resonant state. It is achieved thatthe required dither amplitude is obtained with minimum dithering driving frequency.