Comprehensive analysis of passive generation of parabolic similaritons in tapered hydrogenated amorphous silicon photonic wires

Chao Mei,Feng Li,Qiang Wu,Zhe Kang,Xian Zhou,Jinhui Yuan,Liang Wang,Chongxiu Yu,P K A Wai,Kangping Zhong,Binbin Yan,Xianting Zhang,Xinzhu Sang,Kuiru Wang

doi:10.1038/s41598-017-03840-4

Abstract

Parabolic pulses have important applications in both basic and applied sciences, such as high power optical amplification, optical communications, all-optical signal processing, etc. The generation of parabolic similaritons in tapered hydrogenated amorphous silicon photonic wires at telecom (λ ~ 1550 nm) and mid-IR (λ ≥ 2100 nm) wavelengths is demonstrated and analyzed. The self-similar theory of parabolic pulse generation in passive waveguides with increasing nonlinearity is presented. A generalized nonlinear Schrödinger equation is used to describe the coupled dynamics of optical field in the tapered hydrogenated amorphous silicon photonic wires with either decreasing dispersion or increasing nonlinearity. The impacts of length dependent higher-order effects, linear and nonlinear losses including two-photon absorption, and photon-generated free carriers, on the pulse evolutions are characterized. Numerical simulations show that initial Gaussian pulses will evolve into the parabolic pulses in the waveguide taper designed.

Highlights

Link: Northumbria University has developed Northumbria Research Link (NRL) to enable users to access the University’s research output
The impacts of length dependent higher-order effects, linear and nonlinear losses including two-photon absorption, and photon-generated free carriers, on the pulse evolutions are characterized
We have investigated the generation of parabolic pulses in tapered amorphous silicon (a-Si):H-PhWs and a novel scheme for parabolic pulse generation in nonlinearity increasing waveguides is presented

Summary

Introduction

Link: Northumbria University has developed Northumbria Research Link (NRL) to enable users to access the University’s research output. Several schemes have been proposed to generate parabolic pulses from pulses with different profiles[5, 6, 8, 9, 11] Among these different schemes, parabolic similaritons in amplifiers with normal dispersion[12,13,14,15] or dispersion decreasing waveguides[16, 17] showed distinct advantages. Parabolic similaritons in amplifiers with normal dispersion[12,13,14,15] or dispersion decreasing waveguides[16, 17] showed distinct advantages Self-similar propagation of chirped solitons is found in short tapered media with varying anomalous dispersion[19] or nonlinearity[20]. Generation of parabolic pulses based on asymptotic evolutions have been successfully demonstrated in rare-earth doped fiber www.nature.com/scientificreports/

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