Design of the low-loss waveguide coil for interferometric integrated optic gyroscopes**Project supported by the National Natural Science Foundation of China (Nos. 61274066, 61504138, 61474115) and the National Key Research and Development Program of China (No. 2016YFA02005003).

Abstract

With the development of manufacturing technology, the propagation loss of the planar waveguide is getting lower and lower, and the shot-noise-limited sensitivity of an IIOG will be greatly improved. When the propagation loss is getting lower, improper coupling-out waveguide in the waveguide coil may lead to non-ignorable bending loss and crosstalk because of the small radius of curvature and X-junction. In this paper, different coupling-out waveguides have been designed. After calculation and optimization by the beam propagation method, we found the proper coupling-out waveguide having relatively low propagation loss, which can improve the sensitivity of the IIOG.