Net optical parametric gain in a submicron silicon core fiber pumped in the telecom band

Dong Wu,John Ballato,Joseph Campling,Li Shen,Thomas W Hawkins,Anna C Peacock,Haonan Ren,Ursula J Gibson

doi:10.1063/1.5103272

Abstract

A silicon core fiber (SCF) has been designed and fabricated with a dispersion engineered profile to support broadband optical parametric amplification across the telecom window. The combination of low optical transmission losses and high coupling efficiency of the SCF platform has allowed for an on-off optical parametric gain up to 9 dB, without experiencing gain saturation due to nonlinear absorption, resulting in a net off-waveguide gain of ∼2 dB. The ability to splice the SCFs with conventional silica fiber systems opens a route to compact and robust all-fiber integrated optical parametric amplifiers and oscillators that could find use in telecoms systems.

Highlights

Over the past two decades, optical parametric amplification (OPA) based on four-wave mixing (FWM) has been studied extensively as a means to generate and amplify information signals over a broad wavelength range for communications networks.1 many of the initial investigations employed high-nonlinearity silicabased fibers owing to their immediate compatibility with existing fiber infrastructures,2 over the past decade silicon nanophotonic waveguides produced from the silicon-on-insulator (SOI) platform have emerged as an interesting alternative.3 Compared to the fibers, these on-chip waveguides offer useful advantages in that, owing to their significantly larger nonlinear coefficients, they are extremely compact and offer much lower power thresholds
The nonlinear transmission properties of the silicon core fiber (SCF) were first measured at the pump wavelength
Details of the full set of nonlinear parameters for the tapered SCF can be found in supplementary material, III

Summary

INTRODUCTION

Over the past two decades, optical parametric amplification (OPA) based on four-wave mixing (FWM) has been studied extensively as a means to generate and amplify information signals over a broad wavelength range for communications networks. many of the initial investigations employed high-nonlinearity silicabased fibers owing to their immediate compatibility with existing fiber infrastructures, over the past decade silicon nanophotonic waveguides produced from the silicon-on-insulator (SOI) platform have emerged as an interesting alternative. Compared to the fibers, these on-chip waveguides offer useful advantages in that, owing to their significantly larger nonlinear coefficients, they are extremely compact and offer much lower power thresholds. Other semiconductor materials with lower nonlinear losses have been considered for on-chip wavelength conversion or parametric amplification in the telecom band, including hydrogenated amorphous silicon, silicon nitride, and III–V materials such as AlGaAs, there are ongoing challenges to integrating these materials with standard fiber components and pump sources Glassy materials such chalcogenides and high index doped glass can offer reduced losses, both in terms of transmission and coupling, but they usually require longer device lengths and higher pump powers due to their intrinsic lower refractive indices and nonlinearities. Owing to the larger waveguide dimensions of the SCFs, when compared to the nanophotonic waveguides, no significant saturation of the parametric gain due to nonlinear absorption has been observed up to peak pump powers of ∼17 W We anticipate that this SCF platform will be of interest for a range of nonlinear wavelength conversion applications across the telecommunications bands and beyond, where compact, all-fiber integrated devices are desirable

FIBER DESIGN AND EXPERIMENTAL SETUP

RESULTS

CONCLUSION