High Power, Continuous-wave Supercontinuum Generation in Highly Nonlinear Fibers Pumped with High Order, Cascaded Raman Fiber Amplifiers

TL;DR

This paper demonstrates a novel high-power, continuous-wave supercontinuum source using highly nonlinear fiber pumped by a cascaded Raman amplifier, achieving high power, spectral flatness, and broad bandwidth.

Contribution

It introduces a new method combining cascaded Raman amplification with highly nonlinear fiber for efficient supercontinuum generation in a silica fiber system.

Findings

Generated 35W supercontinuum power with 40% efficiency

Achieved spectral flatness better than 5 dB over 400 nm

Extended supercontinuum spectrum up to approximately 2 microns

Abstract

A novel method for efficient generation of high power, equalized continuous-wave supercontinuum source in an all conventional silica fiber architecture is demonstrated. Highly nonlinear fiber (HNLF) is pumped in its anomalous dispersion region using a novel, high power, L-band laser. The L-band laser encompasses a 6th order cascaded Raman amplifier which is pumped with a high power Ytterbium doped fiber laser and amplifies a low-power, tunable L-band seed source. The supercontinuum generated 35W of power with ~40% efficiency. The Supercontinuum spectrum was measured to have a high degree of flatness of better than 5 dB over 400 nm of bandwidth (1.3 - 1.7 micron, limited by spectrum analyzer range) and a power spectral density in this region of >50 mW/nm. The extent of the SC spectrum is estimated to be upto 2 micron