Showing papers by "Kim P. Hansen published in 2002"
17 Mar 2002
TL;DR: In this article, a highly nonlinear polarization maintaining photonic crystal fiber with zero dispersion at 1.55 /spl mu/m, nonlinear coefficient of 20 (Wkm)/sup -1/ and splice loss to standard technology fiber of 0.3 dB.
Abstract: We demonstrate, for the first time, a highly nonlinear polarization maintaining photonic crystal fiber with zero dispersion at 1.55 /spl mu/m, nonlinear coefficient of 20 (Wkm)/sup -1/ and splice loss to standard technology fiber of 0.3 dB.
59 citations
Patent•
02 May 2002
TL;DR: An apparatus and devices for measuring fluorescence lifetimes of fluorescence sensors for one or more analytes, the apparatus comprising (c) one or multiple reference systems (3,6,7), said reference systems each comprising one ormore reference light sources (3) and being adapted to receive one-or more excitation signals (1a), to produce reference optical signals (6b) in response thereto, and to produce oneor more electrical reference output signals (7b).
Abstract: An apparatus and devices for measuring fluorescence lifetimes of fluorescence sensors for one or more analytes, the apparatus comprising (c) one or more reference systems (3,6,7), said reference systems each comprising one or more reference light sources (3) and being adapted to receive one or more excitation signals (1a), to produce reference optical signals (6b) in response thereto, and to produce one or more electrical reference output signals (7b) in response to one or more excitation signals (1a); and (d) one or more phase detectors (10), said phase detectors being adapted to detect one or more delays of said one or more electrical output signals of said one or more fluorescence sensor systems and said one or more reference systems, and to produce one or more phase output signals; and a method of measuring concentration of one or more analytes using such apparatus and/or devices.
15 citations
17 Mar 2002
TL;DR: In this article, the authors showed that the flattest and broadest spectra are achieved by pumping just below zero-dispersion wavelength and increase in power leads to flatter and broader spectrum.
Abstract: Generation of wide super continua several hundred nanometers wide is possible by pumping in the normal dispersion regime as the nonlinear effects broaden the spectra beyond the zero-dispersion wavelength. When pumping far away from the zero-dispersion wavelength, only self phase modulation (SPM) and Raman scattering contributes to the broadening leading to smooth stable spectra of limited width. Pumping closer to the zero-dispersion wavelength forms very broad spectra, but they are far more sensitive to fluctuations in pumping power and coupling efficiency between fiber and laser. The flattest and broadest spectra are achieved by pumping just below zero-dispersion wavelength and increase in power leads to flatter and broader spectrum. Furthermore, pumping close to the zero-dispersion wavelength enables generation of spectral components at shorter wavelengths below 750 nm through a four-wave mixing process.
7 citations
Proceedings Article•
01 Jan 2002
5 citations
Proceedings Article•
01 Jan 2002
Abstract: Photonic crystal fibres having microstructured air-silica cross sections offer new optical properties compared to conventional fibres. These include novel guiding mechanisms, unique spectral properties and nonlinear possibilities. Recent results within the field are reviewed
5 citations
01 Jan 2002
TL;DR: In this paper, the authors report on the 5 W average power, supercontinuum generation in different air-silica microstructered fibers using a compact largemode-area ytterbium-doped femtosecond fiber amplifier at 1060 nm center wavelength as the excitation source.
Abstract: We report on the 5 W average power, supercontinuum generation in different air-silica microstructered fibers using a compact large-mode-area ytterbium-doped femtosecond fiber amplifier at 1060 nm center wavelength as the excitation source. The flat continuum ranges from 1800 nm. The experimental results are confirmed by numerical simulations, revealing the evolution and fission of higher order solitons as the main contribution to the continuum.
Patent•
02 May 2002
TL;DR: In this paper, an appareil and des dispositifs servant a mesurer la duree de fluorescence utile de detecteurs de fluorescent substances pour une ou plusieurs substances a analyser.
Abstract: L'invention concerne un appareil et des dispositifs servant a mesurer la duree de fluorescence utile de detecteurs de fluorescence pour une ou plusieurs substances a analyser. L'appareil comprend (c) un ou plusieurs systemes de reference (3, 6, 7). Chaque systeme de reference comprend une ou plusieurs sources de lumiere de reference (3). Chaque systeme de reference est adapte pour recevoir un ou plusieurs signaux d'excitation (1a), produire des signaux optiques de reference (6b) en reponse aux signaux d'excitation, et produire un ou plusieurs signaux electriques de sortie de reference (7b) en reponse a un ou plusieurs signaux d'excitation (1a). L'appareil comprend egalement (d) un ou plusieurs detecteurs de phase (10) adaptes pour detecter un ou plusieurs retards d'un ou de plusieurs signaux electriques de sortie d'un ou de plusieurs systemes de detection de fluorescence, et un ou plusieurs systemes de reference; et pour produire un ou plusieurs signaux de sortie de phase. L'invention concerne en outre un procede qui permet de mesurer la concentration d'une ou de plusieurs substances a analyser au moyen de l'appareil et/ou des dispositifs dde l'invention.