Research on multiphysics fields coupling effects of silicon-based lithium niobate electro-optic modulator

Electro-Optic (EO) modulator is one of the key devices in silicon-based optoelectronic integration technology, with its performance closely tied to underlying physical principles, which are essential for gaining deeper insights into the modulator's working mechanisms. Here we focus on silicon-based EO modulator, investigating the various physical fields involved during operation, i.e. optical, electric, thermal, and stress fields, establishing coupling theories between these fields, with particular attention to both the forward and backward processes. The intuitive pictures of these physical fields are simulated, and the coupling effect between different fields and the influence of the modulator electrode structure on them are then quantitatively analyzed. Subsequently, we establish the correlation between the studied physical field and the device's key performance parameters, thereby proposing clear objectives for electrode structure optimization. This study offers insight into the physical principles underlying the performance of modulators, providing a foundational explanation for the alignment or trade-offs between different performance indexes, and then enables a fundamental approach to enhancing device performance.