All-fiber high-power linearly polarized supercontinuum generation from polarization-maintaining photonic crystal fibers

We demonstrate an all-fiber high-power linearly polarized supercontinuum source with polarization-maintaining photonic crystal fibers(PM-PCFs)as the nonlinear medium.The source exhibits an average output power of 3.8 W with a flat spectrum from 480 nm to 2100 nm at the-10 dB level,except for the residual pump peak.The polarization extinction ratio(PER)is measured to be greater than 20 dB at selected sample wavelength points(532 nm,1064 nm and 1550 nm)at the highest pump power level and greater than 20 dB at all wavelengths from 800 nm to 1500 nm at the low pump power level.We also experimentally study the spectral properties when the pump light propagates along different axes of the PM-PCF.The results show that propagating parallel to the slow axis enables a broader spectrum in the PM-PCF in this case,probably due to matching of the dispersion properties with the pump light,which is qualitatively in accordance with the numerical simulation.To our best knowledge,this is the first demonstration of a watt-level linearly polarized supercontinuum source generated from PM-PCFs in an all-fiber structure.

Selective generation of individual Raman Stokes lines using dissipative soliton resonance pulses

Pumped by rectangular-shaped dissipative soliton resonance(DSR)pulses at 1030 nm,selective excitations of Raman Stokes lines of up to third order with extinction ratios of 8 d B and fifth order with extinction ratios of 4 dB are demonstrated experimentally.The rectangular DSR pulses are generated from a dual-amplifier ytterbium-doped figureof-eight mode-locked laser constructed using all 10μm-core-diameter large-mode-area fibers.By varying the two pump powers,the peak power of the output DSR pulses can be continuously tuned from 10 W to 100 W and from 30 W to200 W,respectively,for two different lengths of the nonlinear amplifying loop mirror inside the cavity.High-frequency components are found to correspond to parts of the pulse in the trailing edge when two bandpass filters are used to separate the propagated pulse.Consequently,it provides an all-fiber technique to achieve selective excitation of the Raman shift by adjusting the peak power of the DSR pulse.