High quality factor and high confinement silicon resonators using etchless process

We demonstrate high quality factor and high confinement in a silicon ring resonator fabricated by a thermal oxidation process. We fabricated a 50 μm bending radius racetrack resonator, with a 5 μm coupling region. We achieved an intrinsic quality factor of 760,000 for the fundamental TM mode, which corresponds to a propagation loss of 0.9 dB/cm. Both the fundamental TE and TM modes are highly confined in the waveguide, with effective indices of 3.0 for the TE mode and 2.9 for the TM mode.