RESUMO
We have measured the longitudinal power distribution inside a random distributed feedback Raman fiber laser. The observed distribution has a sharp maximum whose position depends on pump power. The spatial distribution profiles are different for the first and the second Stokes waves. Both analytic solution and results of direct numerical modeling are in excellent agreement with experimental observations.
RESUMO
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 approximately 15 dB bandwidth >260 nm wide (from 1440 to >1700 nm) supercontinuum source is reported with a flatness of <1 dB over 180 nm 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.
Assuntos
Tecnologia de Fibra Óptica/instrumentação , Dispositivos Ópticos , Análise Espectral Raman/instrumentação , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A quasi-continuous wave Dy(3+)-doped ZBLAN fibre laser pumped by a ~1.3 microm Nd:YAG laser and operating at 2.96 microm with an emission linewidth of ~14 nm (FWHM) has been demonstrated. The (6)H(15/2) ? (6)H(9/2), (6)F(11/2) absorption band of Dy(3+)-doped ZBLAN centred at 1.3 microm has been used to pump the (6)H(13/2) ? (6)H(15/2) laser transition. For a 60 cm fibre length, a threshold of 0.5 W and a slope efficiency of ~20% with respect to the absorbed pump power was measured. The experimental slope efficiency was ~45% of the Stokes efficiency limit. The high efficiency relates to low pump ESA losses and an optimised output coupling as compared with previous demonstrations.
