Polymeric microring resonator using nanoimprint technique based on a stamp incorporating a smoothing buffer Layer

A polymeric microring resonator has been proposed and fabricated using the nanoimprint technique based on a stamp incorporating a smoothing buffer layer. It played a pivotal role in improving the sidewall roughness of the waveguide pattern engraved on the stamp and thus reducing its scattering loss. Eventually, the quality factor of the resonator could be enhanced. It also helped narrow down the gap between the ring and the bus effectively to strengthen the coupling between them. For the fabricated device, the quality factor of ∼103 800 and the extinction ratio of ∼11 dB were achieved at 1550 nm, while the estimated scattering loss was reduced from 38 to 0.0005 dB/mm with the help of the smoothing layer.