Characteristics of various sensor devices for a miniature resonant optical gyroscope

Abstract

Subject of study. Using a ring resonator as an example, this paper describes the general operating principle for optical resonators, the characteristics of such resonators, and the relationship between resonator quality factor Q and gyroscope sensitivity. Several sensor devices (optical resonators) were compared for use in the development of a miniature resonant optical gyroscope. These optical resonators were of three different types: a fiber-optic resonator, a whispering gallery mode resonator, and an integrated optical resonator ring. Methodology. The fiber-optic resonator consists of two fiber-optic splitters spliced together, the whispering gallery mode resonator consists of a three-dimensional dielectric structure in which whispering gallery modes are excited, and the integrated optical resonator ring consists of an optical waveguide and closed loop mounted on a common substrate. The characteristics of the high-Q(Q=106−109) whispering gallery mode resonators and fiber-optic resonators were measured using a narrow-band scanning laser and an oscillograph. A simpler approach, with a broadband laser source and an optical spectrum analyzer, was used for the low-Q(Q<106) integrated optical resonators. Main results. Values of Q=5.2×108, Q=4.3×106, and Q=1.1×104 were obtained for a MgF2 disk resonator, fiber-optic disk resonator, and integrated optical resonator, respectively. Practical significance. The whispering gallery mode resonator turns out to be the most promising of these sensor devices since it has the highest Q and the highest accuracy for angular velocity measurements. Fiber optic resonators are competitive but are more sensitive to temperature and external mechanical effects. Integrated optical resonators have the advantage of miniaturization and the ability to include temperature stabilization components and components that provide resistance to mechanical effects.