Theoretical design of a superluminal helium–neon ring laser via coupled passive cavities

Abstract

A helium–neon ring laser cavity is modified by employing variable coupled passive cavities to introduce anomalous dispersion. An equivalent model for the coupled cavities is proposed, and new equations are performed. Theoretical analysis of the parameters is presented in detail, and a novel iterative method is proposed. Gyros using this ring laser are shown in different sensitivity enhancements with limited broadened passive cavity line-width, and the minimal measurable rotation rate is analyzed. The related quantum noise limited line-width is found to be broadened with limitations, which mainly depend on the round trip loss. Fluctuations are induced to analyze parameter influences on enhancements, and a novel modification method concerning mirror reflectivity is proposed for experimental setups. Finally several practical considerations are generally discussed, and some suggestions are proposed for realization. This fast light induced enhancement can be important for present gyros based on a He–Ne ring laser.

On-chip tunable dispersion in a ring laser gyroscope for enhanced rotation sensing

“…Moreover, optical resonators are convenient to provoke critical anomalous dispersion within a narrow-band spectral range; the broadened linewidth is disadvantageous for enhancement sensitivity, and this has been discussed in [18].…”

“…On the other hand, a resonator-based optical gyroscope's sensitivity for measuring rotation is enhanced via using the anomalous dispersion characteristic of superluminal light propagation [12][13][14][15][16][17][18][19]. The idea is a chirped pulse which is either stretched or compressed in time depending on the dispersion of the medium being normal or anomalous.…”

“…The idea is a chirped pulse which is either stretched or compressed in time depending on the dispersion of the medium being normal or anomalous. The experimental schemes including alkali metal vapors [12][13][14] as well as dispersion optical resonators [16][17][18][19] which produced anomalous dispersion into a laser cavity have been proposed. Optical resonators are well suited for this application since they can provide anomalous dispersion using only passive elements, while avoiding the complexities of tailoring the dispersion of stimulated transitions in alkali metals.…”

Theoretical analyses of resonant frequency shift in anomalous dispersion enhanced resonant optical gyroscopes

“…The resonant frequency difference between clockwise (CW) and counterclockwise (CCW) directions can be measured accurately by optical heterodyne technique like in the cases of Ring Laser Gyroscopes (RLGs), which are active resonant optical gyroscopes. In recent years, there has been interest in the development of resonant optical gyroscopes with novel materials234, structures56789101112 and physical effects13141516171819, among which the utilization of fast light for sensitivity enhancement is a potential technique1516171819. Actually, it is the strongly anomalous dispersion that amplifies the Sagnac RFS as well as allows superluminal light propagation.…”

“…There are two schemes to generate anomalous dispersion in ROGs, i.e. coupled-resonator structures151617 and steep negative dispersion materials1819.…”