Efficient four-wave mixing wavelength conversion in a hybrid silicon slot and polymer microring resonator

We present a silicon slot microring resonator for efficient frequency conversion via four-wave mixing (FWM). The slot consists of a narrow silicon waveguide pair with a gap of 80 nm, which is filled with a nonlinear optical polymer. The group velocity dispersion for the microring is controlled by engineering the geometry of the slot structure. Because of the large buildup factor of the slot microring, an FWM conversion efficiency of -27.4 dB is achieved with an optical pump power of less than 1.0 mW. From the measured power dependence of FWM generation, a nonlinear refractive index coefficient of 1.31 × 10^-17 m² W^-1 is obtained at a wavelength of 1562 nm. This work presents a hybrid silicon slot and polymer microring as a potential nonlinear device for applications in integrated photonic devices.