Active resonators based on optical waveguides can significantly enhance the performance of optical gyroscope due to its loss compensation effect. The spontaneous emission noise (SEN) stemmed from optical gain will broaden the linewidth of the resonator and limit the sensitivity and resolution of active resonator optical gyroscope (AROG). In this paper, we modified the sensitivity formula when the spontaneous emission noise is dominant and analyzed theoretically the performance limitations of the AROG. After considering the spontaneous emission noise source, the resolution can be improved through optimizing the design parameters of the AROG
40P<sub>2</sub>O<sub>5</sub>-20Al<sub>2</sub>O<sub>3</sub>-(30-x)Na<sub>2</sub>O-10BaO-xEr<sub>2</sub>O<sub>3</sub> (PANB) glasses with different Er<sup>3+</sup> concentrations were fabricated by the traditional melt quenching method and their spectroscopic properties were investigated. Glass thermal stability is investigated by differential scanning calorimetry (DSC) (T<sub>x</sub>-T<sub>g</sub>=138°C) which indicates a better recrystallization performance than that of fluorophosphates glass and fluorotellurite glass. The derived Judd-Ofelt intensity parameters of Er<sup>3+</sup> doped PANB glass (Ω<sub>2</sub>=18.8, Ω<sub>4</sub>=15.9, Ω<sub>6</sub>=5.38(×10<sup>-20</sup>cm<sup>2</sup> )) indicate higher asymmetry and stronger covalent environment when compared with Er<sup>3+</sup> doped tellurite, fluoride and fluorotellurite glasses. Compared with Er<sup>3+</sup> transitions in other glass hosts, large stimulated emission cross-section and broad full wave at half maximum (FWHM) were found to be 4.58×10<sup>-20</sup>cm<sup>2</sup> and 60 nm centered at ∼1550 nm, respectively. It implies a potential material for infrared lasers and amplifiers.
Optical waveguide is used in most integrated optic devices to confine and guide light in higher refractive index channels. The structures and materials of slot waveguides are reviewed in this paper. Coupled resonator optical waveguides (CROWs) can be used for a rotation sensor with compact size, low power consumption and low cost. The loss determines the ultimate sensitivity of CROW gyros. Resonator-based optical gyroscope’s sensitivity for measuring rotation is enhanced via using the anomalous dispersion characteristic of superluminal light propagation, which can be also generated by using passive optical resonators.