All-fibre heterogeneously-integrated frequency comb generation using silicon core fibre

Silicon core fibre is a highly nonlinear waveguide that combines the benefits of both fibre and planar waveguide systems. Here, the authors demonstrate frequency comb generation using a fully-fibre integrated silicon core fibre as a nonlinear mixer. Originally developed for metrology, optical frequency combs are becoming increasingly pervasive in a wider range of research topics including optical communications, spectroscopy, and radio or microwave signal processing. However, application demands in these fields can be more challenging as they require compact sources with a high tolerance to temperature variations that are capable of delivering flat comb spectra, high power per tone, narrow linewidth and high optical signal-to-noise ratio. This work reports the generation of a flat, high power frequency comb in the telecom band using a 17 mm fully-integrated silicon core fibre as a parametric mixer. Our all-fibre, cavity-free source combines the material benefits of planar waveguide structures with the advantageous properties of fibre platforms to achieve a 30 nm bandwidth comb source containing 143 tones with <3 kHz linewidth, 12 dB flatness, and >30 dB OSNR over the entire spectral region.

Automated summary

This study demonstrates frequency comb generation using a fully-fibre integrated silicon core fibre as a nonlinear mixer. The all-fibre, cavity-free source combines the material benefits of planar waveguide structures with the advantageous properties of fibre platforms to achieve a flat, high power frequency comb source with narrow linewidth and high optical signal-to-noise ratio.