Demonstration of all-silicon thermo-optic tunable microring modulator using AIM photonics’ 300mm process technology

In this work, we demonstrate an all-silicon thermo-optic tunable micro-ring modulator using AIM Photonics’ 300 mm process technology. We used silicon on insulator (SOI) technology to define our waveguides and create our heater elements. The modulator includes a 7-μm-radius silicon ring waveguide and a silicon straight waveguide outside the ring, with a coupling gap. The rib height and width of the modulator are 110 nm and 1 μm, respectively. The 1-μm-wide rib is attached to a full-height silicon of approximately 1 μm width for modulator contact regions. The heater element is positioned after the modulator contact regions and a voltage of up to 8 V is applied to the heater to thermally tune these devices. The modulator heater performance is tested by measuring the resonance shift of the modulators with and without introducing trenches outside the devices. A non-trenched modulator reported to shift the resonance of approximately 1.7 nm at the applied voltages of 8V, while the same applied voltages shift the resonances of approximately 13.7 nm with the trenched modulator. The trenches are expected to trap heat within the device areas, while the non-trenched modulator spreads it outside the device, reducing thermal tuning efficiency. It is noted that the trenched devices are eight times more thermally efficient in tuning the resonances than the non-trenched traditional thermally tunable modulators.