Enhanced efficiency thermo-optic phase-shifter using multi-mode-interference device

We experimentally demonstrate 29.6% power reduction in thermo-optic based Mach-Zehnder interferometer (MZI) (compared to conventional devices) by using multi-mode region of 2x2 Multi-Mode-Interferometer (MMI) as the modulation region. The reported devices show minimal insertion loss penalty compared to generic devices and no additional fabrication complexity.