Double potential well GRIN resonator with self-referencing temperature compensation effect

In this study, a double potential well gradient refractive index (GRIN) resonator with a temperature compensation function was proposed. The composite ion exchange process combining ion diffusion and reverse ion diffusion can be used to control the spatial distribution of ion concentration in materials. Specifically, this process controls the spatial distribution of refractive index in the resonator and forms a double potential well inside the resonator. The two potential wells satisfy the conditions for the formation of stable mode fields. Temperature compensation can be achieved by referencing the modes in the internal and external potential wells. The double potential well GRIN resonator with a diameter of 500 µm has a temperature sensitivity below 0.23 pm/°C and thus effectively achieves temperature compensation.