Optical mode field regulation in GRIN microcavities via ion exchange

This study involved a theoretical analysis of mode field regulation in GRIN microcavities based on ion exchange. Specifically, we analyzed the effects of diffusion time and mutual diffusion coefficient on the refractive index distribution within the microcavity and examined how the spatial refractive index profile influences the mode field distribution. Therefore, the mode field of GRIN microcavities can be precisely controlled by adjusting the ion exchange process parameters. In addition, a composite ion exchange process can be used to construct two potential wells within the microcavity. These two potential wells independently satisfy the condition of mode field distribution for resonance, thereby forming a double potential well GRIN microcavity. On the one hand, the double well GRIN microcavity exhibits a temperature self-compensation effect, allowing for temperature compensation by referencing the two modes in the inner and outer potential wells of the microcavity. On the other hand, the inner and outer modes will interact with each other to regulate the dispersion curve of the microcavity.