Using a 15-μm DFB InGaAsP laser in a passive ring cavity-type fiber gyroscope

Abstract

It has been demonstrated that a 1.5-microm distributed feedback InGaAsP laser can be used as a coherent light source in a passive ring cavity-type fiber gyroscope. A formula for the detector shot noise-limited sensitivity of detection of rotation was derived for this type of gyroscope. Its value in the present experimental setup was estimated as being 0.8 . tau(-1/2) degree/hour, where tau represents the integration time of measurements. Experiments showed that the uncertainty of the detection of rotation was 1.5 degrees /h at tau = 100 s, which was governed by the slight reflection of light at the AR-coated fiber edges and residual frequency fluctuations of the laser.

Directions of development of optical gyroscopes based on passive ring resonators

“…Upward the 80s [5][6][7] research on the optical resonator gyroscope resumed as a part of the development of fiber gyroscopes. In classical interference fiber-optic gyroscopes the angular velocity is measured by the phase difference of the oncoming waves passing once through the contour of the Sagnac interferometer formed by a fiber coil.…”

Triangularly phase-modulated optical fiber ring resonator sensor

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] This optical device has been used for sensor applications, 7 laser-diode frequency stabilization, 8 and in fiber-optic gyroscopes. 9 -' 4 In these applications, in order to obtain a highly sensitive output signal for a given change in the optical path length or laser frequency, the linewidth of the resonator is in general the most important parameter. The intensity variation at the maximum sensitive position of the transmittance of the resonators 8 or a differential S-shaped output signal obtained at the resonance frequency 9 has been used to extract information on the change in optical phase delay.…”

“…9 -' 4 In these applications, in order to obtain a highly sensitive output signal for a given change in the optical path length or laser frequency, the linewidth of the resonator is in general the most important parameter. The intensity variation at the maximum sensitive position of the transmittance of the resonators 8 or a differential S-shaped output signal obtained at the resonance frequency 9 has been used to extract information on the change in optical phase delay. The ring resonator is more sensitive than Mach-Zehnder-type interferometers, but its dynamic range and linearity characteristics are limited by the resonator linewidth and thus are inferior to Mach-Zehnder-type interferometers.…”