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

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. [ABSTRACT FROM AUTHOR]