Broadband, stable and highly coherent supercontinuum generation at telecommunication wavelengths in an hydrogenated amorphous silicon waveguide

TL;DR

This paper demonstrates that hydrogenated amorphous silicon waveguides can generate a broad, coherent supercontinuum at telecommunication wavelengths with low pulse energy, showing advantages over crystalline silicon.

Contribution

The study provides experimental and numerical evidence of supercontinuum generation in a-Si:H waveguides, highlighting their high coherence, stability, and superior performance compared to c-Si.

Findings

Supercontinuum spans over 500 nm in a-Si:H waveguides.

Supercontinuum is highly coherent and stable under femtosecond pulses.

a-Si:H outperforms c-Si in broadband low-power supercontinuum generation.

Abstract

Hydrogenated amorphous silicon (a:Si-H) has recently been recognized as a highly nonlinear CMOS compatible photonic platform. We experimentally demonstrate the generation of a supercontinuum (SC) spanning over 500 nm in a-Si:H photonic wire waveguide at telecommunication wavelengths using femtosecond input pulse with energy lower than 5 pJ. Numerical modeling of pulse propagation in the waveguide, based on the experimentally characterized dispersion profile, shows that the supercontinuum is the result of soliton fission and dispersive wave generation. It is demonstrated that the SC is highly coherent and that the waveguides do not suffer from material degradation under femtosecond pulse illumination. Finally, a direct comparison of SC generation in c-Si and a-Si:H waveguides confirms the higher performances of a-Si:H over c-Si for broadband low power SC generation at telecommunication wavelengths.