Abstract

The Kerr nonlinear optical performance of silicon nanowire waveguides integrated with 2D layered graphene oxide (GO) films is theoretically studied and optimized based on experimentally measured linear and nonlinear optical parameters of the GO films. The strong mode overlap between the silicon nanowires and highly nonlinear GO films yields a significantly enhanced Kerr nonlinearity for the hybrid waveguides. A detailed analysis for the influence of waveguide geometry and GO film thickness on the propagation loss, nonlinear parameter, and nonlinear figure of merit (FOM) is performed. The results show that the effective nonlinear parameter and nonlinear FOM can be increased by up to ∼52 and ∼79 times relative to bare silicon nanowires, respectively. Self-phase modulation (SPM)-induced spectral broadening of optical pulses is used as a benchmark to evaluate the nonlinear performance, examining the trade-off between enhancing Kerr nonlinearity and minimizing loss. By optimizing the device parameters to balance this, a high spectral broadening factor of 27.8 can be achieved – more than 6 times that achieved in previous experiments. Finally, the influence of pulse chirp, material anisotropy, and the interplay between saturable absorption and SPM is also discussed, together with the comparison between the spectral broadening after going through GO-coated and graphene-coated silicon waveguides. These results provide useful guidance for optimizing the Kerr nonlinear optical performance of silicon waveguides integrated with 2D layered GO films.

Nonlinear spectral broadening of a dual-carrier electro-optic frequency comb in a graphene oxide cladded silicon-rich nitride hybrid waveguide

Partha Mondal and Shankar K. Selvaraja
Appl. Opt. 61(27) 7852-7860 (2022)

Enhanced optical Kerr nonlinearity of MoS₂ on silicon waveguides

Linghai Liu, Ke Xu, Xi Wan, Jianbin Xu, Chi Yan Wong, and Hon Ki Tsang
Photon. Res. 3(5) 206-209 (2015)

Amorphous silicon nanowires combining high nonlinearity, FOM and optical stability

C. Grillet, L. Carletti, C. Monat, P. Grosse, B. Ben Bakir, S. Menezo, J. M. Fedeli, and D. J. Moss
Opt. Express 20(20) 22609-22615 (2012)

Photothermal nonlinearity and optical bistability in a graphene–silicon waveguide resonator

Cameron Horvath, Daniel Bachman, Rob Indoe, and Vien Van
Opt. Lett. 38(23) 5036-5039 (2013)

Ultra-large nonlinear parameter in graphene-silicon waveguide structures

Christine Donnelly and Dawn T. H. Tan
Opt. Express 22(19) 22820-22830 (2014)