High efficiency supercontinuum generation using ultra-long Raman fiber cavities

Supercontinuum generation in a multi-fiber ultra-long Raman fiber laser cavity is experimentally investigated for the first time. We demonstrate significantly enhanced spectral flatness and supercontinuum generation efficiency using only conventional single mode silica fiber. With a pump power of only 1.63W a ~15dB bandwidth >260 nm wide (from 1440 to >1700nm) supercontinuum source is reported with a flatness of <1dB over 180nm using an optimised hybrid TW/HNLF cavity. We address the dependence of the supercontinuum spectrum on the input pump power and ultra-long Raman cavity

Long-distance soliton transmission through ultralong fiber lasers

We present the first experimental demonstration (to our knowledge) of long-distance unperturbed fundamental optical soliton transmission in conventional single-mode optical fiber. The virtual transparency in the fiber required for soliton transmission, over 15 complete periods, was achieved by using an ultralong Raman fiber laser amplification scheme. Optical soliton pulse duration, pulse bandwidth, and peak intensity are shown to remain constant along the transmission length. Frequency-resolved optical gating spectrograms and numerical simulations confirm the observed optical soliton dynamics

Improved supercontinuum generation by dispersion tuning and dual wavelength pumping

Supercontinuum generation in ultra-long Raman fibre laser cavities is compared for a range of fibre dispersions in the anomalous and normal regimes. For normal dispersion improved performance and efficiency is achieved using dual wavelength pumping

165 km ultra-long Raman fibre laser in the C-band

We present the first experimental demonstration of a Raman fibre laser operation with a resolvable ~0.6 kHz mode spacing operating at 1551nm. Our laser has a record cavity length of 165 km

165 km ultra-long Raman fibre laser in the C-band

We present the first experimental demonstration of a Raman fibre laser operation with a resolvable ~0.6 kHz mode spacing operating at 1551nm. Our laser has a record cavity length of 165 km

Signal power excursion and pump efficiency in quasi-lossless ultra-long Raman laser links

Performance optimisation of ultra-long Raman laser links is studied theoretically and experimentally. We observe that it is possible to reduce signal power excursion by adjusting FBG reflectivity without compromising pump efficiency

Effect of fibre base and reflectors profile on the efficiency of ultra- long laser cavities

We study the effect of fibre base and grating profile on the efficiency of ultra-long Raman lasers. We show that for the studied parameters, FBG profile does not affect the performance when operating away from the zero-dispersion wavelength