3,317 research outputs found
Low noise all-fiber amplification of a coherent supercontinuum at 2 \mu m and its limits imposed by polarization noise
We report the amplification of an all-normal dispersion supercontinuum pulse
in a Thulium / Holmium co-doped all-fiber chirped pulse amplification system.
With a -20 dB bandwidth of more than 300 nm in the range 1800-2100 nm the
system delivers high quality 66 fs pulses with more than 70 kW peak power
directly from the output fiber. The coherent seeding of the entire emission
bandwidth of the doped fiber and the stability of the supercontinuum generation
dynamics in the silicate glass all-normal dispersion photonic crystal fiber
result in excellent noise characteristics of the amplified ultrashort pulses
Chalcogenide-glass polarization-maintaining photonic crystal fiber for mid-infrared supercontinuum generation
In this paper, we report the design and fabrication of a highly birefringent
polarization-maintaining photonic crystal fiber (PM-PCF) made from chalcogenide
glass, and its application to linearly-polarized supercontinuum (SC) generation
in the mid-infrared region. The PM fiber was drawn using the casting method
from As38Se62 glass which features a transmission window from 2 to 10
and a high nonlinear index of 1.13.10mW. It has a
zero-dispersion wavelength around 4.5 and, at this wavelength, a large
birefringence of 6.10 and consequently strong polarization maintaining
properties are expected. Using this fiber, we experimentally demonstrate
supercontinuum generation spanning from 3.1-6.02 and 3.33-5.78
using femtosecond pumping at 4 and 4.53 , respectively. We
further investigate the supercontinuum bandwidth versus the input pump
polarization angle and we show very good agreement with numerical simulations
of the two-polarization model based on two coupled generalized nonlinear
Schr\"odinger equations.Comment: 13 pages, 8 figure
Multiple-octave spanning mid-IR supercontinuum generation in bulk quadratic nonlinear crystals
Bright and broadband coherent mid-IR radiation is important for exciting and
probing molecular vibrations. Using cascaded nonlinearities in conventional
quadratic nonlinear crystal like lithium niobate, self-defocusing near-IR
solitons have been demonstrated that led to very broadband supercontinuum
generation in the visible, near-IR and short-wavelength mid-IR. Here we conduct
an experiment where a mid-IR crystal pumped in the mid-IR gives multiple-octave
spanning supercontinua. The crystal is cut for noncritical interaction, so the
three-wave mixing of a single mid-IR femtosecond pump source leads to highly
phase-mismatched second-harmonic generation. This self-acting cascaded process
leads to the formation of a self-defocusing soliton at the mid-IR pump
wavelength and after the self-compression point multiple octave-spanning
supercontinua are observed (covering 1.6-m). The results were recorded
in a commercially available crystal LiInS pumped in the 3-m range,
but other mid-IR crystals can readily be used as well.Comment: submitted to APL Photonic
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