Search results for "Supercontinuum"
showing 10 items of 128 documents
Generation of supercontinuum in erbium-doped microstructured optical fibers
2009
We present experimental results on supercontinuum (SC) generation in Er-doped microstructured optical fibers (MOF) pumped with nanosecond pulses at 1064 nm. The Er doping increases the effective nonlinear refractive index [1]. As a result, nonlinear interactions are enhanced and broad supercontinuum spectra are generated with relatively low pump power. Supercontinuum spectra generated in two fibers with the zero dispersion wavelengths (ZDW) close to the pump wavelength are presented. The first MOF is an endlessly singlemode fiber with normal dispersion at the pump wavelength, while the second fiber is a large air-filling fraction MOF with anomalous dispersion at 1064 nm.
Flat supercontinuum generation pumped by amplified noise-like pulses from a figure-eight erbium-doped fiber laser
2017
The conditions to obtain noise-like pulses (NLPs) from a figure-eight fiber laser (F8L) and their application for supercontinuum (SC) generation in the anomalous dispersion regime are reported. The F8L is designed to remove the undesired low-intensity background radiation from pulse emission, generating NLPs with a 3 dB spectral bandwidth of 17.43 nm at the fundamental repetition frequency of 0.8 MHz. After amplification, NLPs reach a maximum average power of 9.2 mW and 123.32 nm spectral bandwidth. By controlling the amplifier pump power, flat SC generation is demonstrated through both a 800 m long spool of SMF-28 fiber and a piece of 5 m long highly nonlinear optical fiber. The results de…
Telecom to mid-infrared supercontinuum generation in a silicon germanium waveguide
2015
We report the first demonstration of broadband supercontinuum generation in silicon-germanium waveguides. Upon propagation of ultra-short femtosecond pulses in a 3-cm-long waveguide, the broadening extended from 1.455µm to 2.788µm (at the −30-dB point).
Supercontinuum generation in silicon waveguides based on optical wave-breaking
2014
We theoretically find the third order dispersion that optimizes the spectral broadening induced by optical wave-breaking. It produces supercontinuum spectra spanning beyond 2=3 of an octave in a silicon waveguide pumping at 1550 nm.
Octave-spanning coherent supercontinuum generation in a step-index tellurite fiber and towards few-cycle pulse compression at 2 μ m
2021
Abstract We experimentally demonstrate 140-THz bandwidth (at −20 dB) supercontinuum generation in a 10 cm-long all-normal dispersion step-index tellurite fiber pumped by a turn-key femtosecond fiber laser emitting at 2 . 11 μ m at a repetition rate of 19 MHz. The soliton self-frequency shifted thulium-doped fiber mode-locked laser emits initial transform-limited pulses, with 85-fs pulse duration, that are subsequently quasi-linearly chirped (over more than 50 THz) during the above nJ-level nonlinear propagation. Moreover, we numerically demonstrate the possible pulse compression down to 12 fs by means of additional linear propagation in a standard step-index fluoride fiber with anomalous di…
Tapering photonic crystal fibres for supercontinuum generation with nanosecond pulses at 532nm
2008
Experimental results on supercontinuum generation in photonic crystal fibre tapers using pump pulses of 7 ns duration at 532 nm are presented. Photonic crystal fibre tapers with the first wavelength of zero dispersion around 532 nm were fabricated. The generation of supercontinuum was investigated in normal and anomalous dispersion regimes. Supercontinuum spectra spanning more than 400 nm in the visible region are reported.
Control of the chromatic dispersion of photonic crystal fibers for supercontinuum and photon pairs generation
2011
The interplay between chromatic dispersion and nonlinear effects is crucial for an efficient exploitation of non linear propagation in photonic crystal fibers (PCF). Once a PCF preform has been prepared, changing the parameters that control the fabrication process it is possible to adjust the dispersion properties of the fiber. In addition, it is particularly useful to develop postprocessing techniques that enable a fine adjustment of the dispersion along a section of PCF. The tapering of PCF, using a fusion and pulling technique, has been established as a rather useful technique to engineer the dispersion properties along tens of centimeters. Some of our recent experiments demonstrate that…
Suspended core tellurite glass optical fibers for infrared supercontinuum generation
2011
International audience; We report the fabrication and characterization of tellurite TeO(2)-ZnO-Na(2)O (TZN) microstructured suspended core optical fibers (MOFs). These fibers are designed for infrared supercontinuum generation with zero dispersion wavelength (ZDW) at 1.451 mu m. The measured losses at this wavelength are approximately 6 dB/m for a MOF with a 2.2 mu m diameter core. The effective area of a particular fiber is 3.5 mu m(2) and the nonlinear coefficient is calculated to be 437 W(-1)km(-1). By pumping a 20 cm long fiber at 1.56 mu m with a sub-nj femtosecond laser source, we generate a supercontinuum (SC) spanning over 800 nm in the 1-2 mu m wavelength range.
Tellurites fibers for infrared supercontinuum sources : opto-geometric profiles and extrinsic absorptions management
2016
This PhD thesis work focuses on the synthesis and purification of vitreous materials used for the development of waveguides with varied profiles, dedicated to supercontinuum (SC) generation between 1 and 5 μm.Concerning the purification of tellurite glasses, several leads were followed, but best results are obtained for the purification of the TeO2-ZnO-Na2O glassy system by the means of zinc fluoride. Attenuation measurements performed on several meter-long single-index fiber samples reveal the nearly complete elimination of water-related absorptions between 3 and 4 μm (OH ions concentration lower than 1 ppm mass.). Such water-purified glasses were firstly dedicated to microstructured optic…
Fibres optiques à coeur supendu en verre d'oxyde de tellure et génération d'effets non linéaires dans l'infrarouge au-delà de 2 microns
2012
The work reported in this thesis deals with the fabrication of suspended core tellurite microstructured optical fibers (MOFs) for supercontinuum generation beyond 2 µm. In order to reach our aim, we first studied thermal and optical properties of TeO2-ZnO-R2O and TeO2-WO3-R2O (where R = Li, Na and K) glasses. The glass 80TeO2-10ZnO-10Na2O (molar %) has been chosen in order to make MOFs for characterization of the generated non linear optical effects. Synthesis performed under dry and oxidative atmosphere allowed us to reduce the hydroxyl groups concentration by a factor of 30 compared to fabrication in air atmosphere. Use of dehydrating agents (ZnF2 and TeCl4) allowed to reduce again the OH…