Study of Wavelength Temperature Stability of Multifunctional Integrated Optical Chips Applied on Fiber Optic Gyroscopes

In this paper, we theoretically analyze the wavelength temperature stability of multifunctional integrated optical chips (MIOCs) applied on fiber optic gyroscopes (FOGs). This study is critical for improving the temperature stability of the FOG scale factor, which is a significant parameter used to evaluate the dynamic characteristics of FOGs. Analytical and multiphysics simulations uncover two significant new predictions. First, changes in environmental temperature can lead to misalignment of the coupling structure between the chip and fiber, which is the main reason for the deterioration of the MIOC wavelength temperature stability. Second, misalignment caused by temperature changes is related to the initial alignment parameters of the coupling structure. Therefore, we can effectively improve the wavelength temperature stability of an MIOC by correctly choosing the initial alignment state of the coupling structure. Space coupling experiments are also presented to verify these predictions, and the experimental and simulation results are in good agreement.