Enhanced Spectral Broadening of Femtosecond Optical Pulses in Silicon Nanowires Integrated with 2D Graphene Oxide Films

Micromachines

Yuning Zhang¹  Yunyi Yang¹  Jiayang Wu¹  Linnan Jia¹  David J. Moss¹  Yang Qu¹  Baohua Jia² 

[1] Optical Sciences Center, Swinburne University of Technology, Hawthorn, VIC 3122, Australia;School of Science, RMIT University, Melbourne, VIC 3001, Australia;

关键词: nonlinear optics;    silicon photonics;    graphene oxide;    femtosecond optical pulses;    self-phase modulation;   

DOI  :  10.3390/mi13050756

来源: DOAJ

【 摘 要 】

We experimentally demonstrate enhanced spectral broadening of femtosecond optical pulses after propagation through silicon-on-insulator (SOI) nanowire waveguides integrated with two-dimensional (2D) graphene oxide (GO) films. Owing to the strong mode overlap between the SOI nanowires and the GO films with a high Kerr nonlinearity, the self-phase modulation (SPM) process in the hybrid waveguides is significantly enhanced, resulting in greatly improved spectral broadening of the femtosecond optical pulses. A solution-based, transfer-free coating method is used to integrate GO films onto the SOI nanowires with precise control of the film thickness. Detailed SPM measurements using femtosecond optical pulses are carried out, achieving a broadening factor of up to ~4.3 for a device with 0.4-mm-long, 2 layers of GO. By fitting the experimental results with the theory, we obtain an improvement in the waveguide nonlinear parameter by a factor of ~3.5 and in the effective nonlinear figure of merit (FOM) by a factor of ~3.8, relative to the uncoated waveguide. Finally, we discuss the influence of GO film length on the spectral broadening and compare the nonlinear optical performance of different integrated waveguides coated with GO films. These results confirm the improved nonlinear optical performance of silicon devices integrated with 2D GO films.

【 授权许可】

Unknown