Michelson interferometer modulator based on hybrid silicon and lithium niobate platform

We propose and demonstrate a hybrid silicon and lithium niobate Michelson interferometer modulator (MIM) with a reduced half-wave voltage-length product compared to a Mach-Zehnder modulator. The modulator is based on seamless integration of a high-contrast waveguide based on lithium niobate—a widely used modulator material—with compact, low-loss silicon circuitry. The present device demonstrates a half-wave voltage-length product as low as 1.2 V cm and a low insertion loss of 3.3 dB. The 3 dB electro-optic bandwidth is approximately 17.5 GHz. The high-speed modulations are demonstrated at 32 Gbit/s and 40 Gbit/s with the extinction ratio of 8 dB and 6.6 dB, respectively. The present device avoids absorption loss and nonlinearity in conventional silicon modulators and demonstrates the lowest half-wave voltage-length product in lithium niobate modulators. The hybrid MIM demonstrates high-speed data modulation showing potential in future optical interconnects.