0000000000315316
AUTHOR
Esben Ravn Andresen
All-fiber transform-limited spectral compression by self-phase modulation of amplitude shaped pulses
International audience; We demonstrate efficient spectral compression of picosecond pulses in an all-fiber configuration at telecommunication wavelengths. Thanks to parabolic pulse shaping, a spectral compression by a factor 12 is achieved with an enhanced Strehl ratio.
Obtention d'impulsions en limite de Fourier par compression spectrale réalisée dans une fibre optique
National audience; Nous démontrons la compression spectrale d'impulsions picosecondes dans un montage totalement fibré aux longueurs d'onde des télécommunications optiques. Grâce à un façonnage préalable du profil d'intensité en une parabole, un facteur de compression dépassant 10 est démontré avec un facteur de Strehl significativement augmenté par rapport à une impulsion de forme sécante hyperbolique.
Spectral analog of the Gouy phase shift
We demonstrate the existence of the spectral phase shift a pulse experiences when it is subjected to spectral focusing. This $\frac{\ensuremath{\pi}}{2}$ phase shift is the spectral analog of the Gouy phase shift a 2D beam experiences when it crosses its focal plane. This spectral Gouy phase shift is measured using spectral interference between a reference pulse and a negatively chirped parabolic pulse experiencing spectral focusing in a nonlinear photonic crystal fiber. To avoid inherent phase instability in the measurement, both reference and parabolic pulses are generated with a $4\mathrm{\text{\ensuremath{-}}}f$ pulse shaper and copropagate in the same fiber. We measure a spectral phase…
Experimental observation of the spectral Gouy phase shift
We experimentally observe and measure the spectral phase shift of a pulse subjected to spectral focusing. We find a phase shift of π/2, reaffirming the Gouy phase shift as a general consequence of wave confinement whether in space/momentum or frequency/time coordinates.
Transform-limited spectral compression by self-phase modulation of amplitude-shaped pulses with negative chirp
International audience; Spectral compression by self-phase modulation of amplitude- and phase-shaped pulses is demonstrated as superior compared to pulses that have only been phase shaped. We synthesize linearly negatively chirped parabolic pulses, which we send through a nonlinear photonic crystal fiber, in which self-phase modulation compresses the spectrum of the pulses to within 20% of the Fourier transform limit.
All-fiber spectral compression of picosecond pulses at telecommunication wavelength enhanced by amplitude shaping
International audience; We demonstrate efficient spectral compression of picosecond pulses in an all-fiber configuration at telecommunication wavelengths. A spectral compression by a factor 12 is achieved. Performing temporal shaping with a parabolic pulse significantly improves the spectral compression with much lower substructures and an enhanced Strehl ratio.
Experimental control over soliton interaction in optical fiber by pre-shaped input field
Interactions between femtosecond solitons in a nonlinear photonic-crystal fiber are of fundamental interest. But many practical applications would abound if solitons could be arbitrarily superposed into multiples in the fiber. Here, we numerically and experimentally demonstrate a first step towards this aim, the creation of a soliton pair with arbitrary relative phase, delay, and frequency throughout almost the entire output parameter space with the aid of a pre-shaped fiber input field.
Impact of initial pulse shape on the nonlinear spectral compression in optical fibre
International audience; We theoretically study the effects of the temporal intensity profile of the initial pulse on the nonlinear spectral compression process arising from nonlinear propagation in an optical fibre. Various linearly chirped input pulse profiles are considered, and their dynamics is explained with the aid of time-frequency representations. While initially parabolic-shaped pulses show enhanced spectral compression compared to Gaussian pulses, no significant spectral narrowing occurs when initially super-Gaussian pulses are used. Triangular pulses lead to a spectral interference phenomenon similar to the Fresnel bi-prism experiment.
Sensitizer exchange dynamics in air and solvent filled semiconductor nanocavities
Multiple dye binding sites and their exchange in equilibrium in air and solvent filled sensitized titanium oxide nanocavities were identified by 2DIR spectroscopy. Binding geometry and flexibility may influence electron injection efficiency of solar cells.
Nonlinear pulse shaping by coherent addition of multiple redshifted solitons
International audience; The injection of a phase- and amplitude-shaped pulse into a photonic-crystal fiber provides additional degrees of freedom that can significantly influence the nature of nonlinear propagation and nonlinear and dispersive interactions. This strong sensitivity of nonlinear effects-particularly the Raman soliton self-frequency shift-greatly extends the parameter space available to generate tailored output fields for applications such as microscopic imaging. By numerical simulations, we identify the relevant interpulse interactions, and we experimentally demonstrate the additional capabilities of this nonlinear pulse-shaping method.