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ABSTRACT: It is now commonly accepted that, in large pitch hollow-core 'kagomé' lattice fibers, the loss spectrum is related to resonances of the thin silica webs in the photonic crystal cladding. Moreover, coherent scattering from successive holes' layers cannot be obtained and adding holes' layers does not decrease the loss level. In this communication, cross-comparison of experimental data and accurate numerical modeling is presented that helps demonstrate that waveguiding in large pitch hollow-core fibers arises from the antiresonance of the core surround only and does not originate from the photonic crystal cladding. The glass webs only mechanically support the core surround and are sources of extra leakage. Large pitch hollow-core fibers exhibit features of thin walled and thick walled tubular waveguides, the first one tailoring the transmission spectrum while the second one is responsible for the increased loss figure. As a consequence, an approximate calculus, based on specific features of both types of waveguides, gives the loss spectrum, in very good agreement with experimental data. Finally, a minimalist hollow-core microstructured fiber, the cladding of which consists of six thin bridges suspending the core surround, is proposed for the first time.
Optics Express 03/2010; 18(5):5142-50. · 3.59 Impact Factor
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ABSTRACT: Femtosecond single-pulsed supercontinua (SC) are produced in a short sub-cm piece of photonic crystal fiber. The SC span from 450 nm to more than 1.1 mum with 1-nJ energy injection. UV light down to 340 nm is observed with increased injection power. Using such a single-pulsed SC we implemented a compact transient absorption spectrometer with broadband detection and 150-fs FWHM time resolution to monitor the ultrafast dynamics of the electronic states of malachite green in ethanol excited to the S(2) state. The full spectral evolution is observed from 450 nm to 1050 nm, with high sensitivity and a signal-to-noise ratio as high as 1000.
Optics Express 12/2007; 15(24):16124-9. · 3.59 Impact Factor
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ABSTRACT: The hollow core of an air-silica microstructured fiber was selectively filled with an alcoholic solution containing a laser dye (coumarin 515). This innovative liquid core fiber was used to build an efficient intensity autocorrelator operating by transverse imaging of the nonlinear fluorescence. Accurate measurement of pulse duration in the picosecond regime with submilliwatt average power has been demonstrated in the near infrared.
Applied Physics Letters 08/2006; 89(6):061117-061117-3. · 3.84 Impact Factor
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Sylvie Yiou,
Philippe Delaye,
Anne Rouvie,
Jordi Chinaud,
Robert Frey,
Gérald Roosen, Pierre Viale,
Sébastien Février,
Philippe Roy,
Jean-Louis Auguste,
Jean-Marc Blondy
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ABSTRACT: We show that high efficiency stimulated Raman scattering can be obtained using hollow core photonic crystal fiber with the core filled with a low refractive index nonlinear liquid. This new architecture opens new perspectives in the development of nonlinear functions as any kind of nonlinear liquid media can now be used to implement them, with original properties not accessible with silica core fibers.
Optics Express 07/2005; 13(12):4786-91. · 3.59 Impact Factor
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ABSTRACT: The modal behavior of a ∼500-μm2 mode area photonic bandgap fiber was theoretically and experimentally investigated. First, a full-vector finite element algorithm was used to predict the modal properties. Then, a low-coherence reflectometry technique was employed to measure the chromatic dispersion and evaluate the number of guided modes. A short length of fiber was found to guide only two LP modes with different attenuation coefficients. The measured chromatic dispersion of the fundamental mode was found in close agreement with theoretical value. The large positive dispersion is theoretically explained by the positive waveguide dispersion induced by weak a spectral variation of radial electric field distribution in Bragg fibers.
Photonics and Nanostructures - Fundamentals and Applications.
