Enhancing Optical Non linearity in a Nonstoichiometric SiN Waveguide for Cross-Wavelength All-Optical Data Processing

Nonstoichiometric SiNx with enhancing optical nonlinearity is enabled to facilitate the waveguide microring resonator for cross-wavelength all-optical data processing applications. The Si/N composition ratio of the non-stoichiometric SiNx can be detuned from stoichiometric to Si-rich by adjusting the SiH4/NH3 fluence ratios. Under pumping with incoming pulsed data, the comb-like transmittance of the nonstoichiometric SiNx microring resonator can spectrally red-shift by 100 pm as its effective refractive index changed by more than 1 order of magnitude due to the enhanced nonlinear Kerr effect. The enlarged refractive index of Delta n = 1.6 x 10(-4) with increasing nonlinear refractive index to n(2) = 1.6 x 10(-13) cm(2)/W at 1550 nm is observed at a Si concentration of 66.2% in the Si-rich SiNx film. In application, a cross-wavelength all-optical data conversion/inversion processor based on the nonstoichiometric SiNx microring resonator is presented. The dense nanoscale Si content formed by a higher Si/N composition ratio of the SiNx contributes to an enhanced Kerr effect based optical nonlinear switching, which enables the optimized 12 Gbit/s all-optical conversion of the pulsed return-to-zero on-off-keying (RZ-OOK) data with converted or inverted format. The photon lifetime of similar to 19 ps in the Si-rich SiNx microring resonator cavity can support the Si-rich SiNx all-optical Kerr switch with a maximal bandwidth of up to 50 GHz.