Fabrication and Characterization of Bragg Reflector Slow-Light Waveguide with Oxide Lateral Confinement

Slowing light in Bragg reflector waveguides enables us to miniaturize optical devices. A platform of low-loss slow-light waveguides with lateral optical confinement is required. We propose and fabricate a slow-light waveguide with lateral oxide confinement using an equivalent index difference in a lateral direction. The coupling and propagation losses are evaluated from the waveguide length dependence of insertion losses. The propagation loss is in the range of 0.1 dB/μm for transverse magnetic (TM) modes. Also, it is predicted that the propagation loss can be reduced if we replace a top Au/distributed Bragg reflector (DBR) hybrid mirror with a Si/SiO 2 DBR.