Nanoscale C-Rich Si_xC_(1-x) Bus/Ring Waveguide Based Cross-Wavelength Data Converter

摘要

The carbon-rich silicon carbide (C-rich Si_xC_(1-x)) micro-ring channel waveguide with asymmetric core aspect is demonstrated for all-optical cross-wavelength pulsed return-to-zero on-off keying (PRZ-OOK) data conversion. Enhanced nonlinear optical Kerr switching enables 12-Gbit per second data processing with optimized modulation depth. The inverse tapered waveguide at end-face further enlarges the edge-coupling efficiency, and the asymmetric channel waveguide distinguishes the polarization modes. To prevent data shape distortion, the bus/ring gap spacing is adjusted to control the quality factor (Q-factor) of the micro-ring. Designing the waveguide cross section at 500 × 350 nm~2 provides the C-rich Si_xC_(1-x) channel waveguide to induce strong transverse electric mode (TE-mode) confinement with a large Kerr nonlinearity of 2.44 × 10~(-12) cm~2 W~(-1). Owing to the trade-off between the Q-factor and the on/off extinction ratio, the optimized bus/ring gap spacing of 1400 nm is selected to provide a coupling ratio at 5-6% for compromising the modulation depth and the switching throughput. Such a C-rich Si_xC_(1-x) micro-ring with asymmetric channel waveguide greatly enhances the cross-wavelength data conversion efficiency to favor its on-chip all-optical data processing applications for future optoelectronic interconnect circuits.