Search results for "Note"
showing 10 items of 10709 documents
On the possibility of observing bound soliton pairs in a "wave-breaking-free" mode-locked fiber laser
2007
To generate ultrashort pulses with higher energy in passively mode-locked fiber lasers, several groups have recently focused on the development of laser cavities operating in normal path-averaged dispersion, with a view to achieve wave-breaking-free operation. The mode-locking mechanism in fiber laser play a key role in providing scalability limitation: for instance, nonlinear polarization evolution can be overdriven. Furthermore, the differential gain of the doped fiber decreases along with the traveled distance. From all of these limitations, it follows that power scalability is always bounded for virtually any mode-locked laser cavity design. In general, the consequence is the emergence …
Cascadability and efficiency of a saturable absorber device inserted into a SMF transmission line for future 160-Gbit/s all-optical reshaping applica…
2007
In this prospective work, we analyze the cascadability and reshaping properties of a quantum well microcavity saturable absorber (SA) device cascaded inside a RZ-signal SMF-based transmission line to annihilate the ghost-pulse phenomenon taking place in the "...01010101..." 160-Gbit/s 2-bit pattern.
Interactions and transformations of dissipative optical bullets
2007
Nonlinear dissipation provides distinctive dynamical properties to optical bullets. According to the system parameters, the dynamical properties of single bullets range from fully stable to pulsating and instable bullets. We are here interested in the following stage, namely the interaction between several optical bullets.
Near-field observation of surface plasmon polariton propagation on thin metal stripes
2001
International audience; We use a photon scanning tunneling microscope to probe the field of surface plasmon polariton modes excited on finite-width thin metal films (metal stripes). We first investigate the coupling between surface plasmons launched by a focused beam on a homogeneous thin film and the modes sustained by metal stripes of different widths. We show that. if the width of the metal stripe is about a few micrometers, a strong coupling with the stripe modes can be achieved at visible frequencies. A sharp transverse confinement of the field associated with the surface plasmon modes propagating on the metal stripe is unambiguously observed on the constant height photon scanning tunn…
Performance optimisation of dual-pump NALM fibre laser using machine learning inference
2018
We apply predictive regression to find optimum operating regimes in a recently proposed layout of a flexible Figure-8 laser having two independently pumped segments of active fibre in its bidirectional ring.
Collisional effects on spectral line shape from the Doppler to the collisional regime: A rigorous test of a unified model
2000
International audience; The paper presents high resolution Raman investigations of the Q(1) line of H-2 in Ar mixture from low density (Doppler regime) to high density (collisional regime) analyzed with a unique line shape profile. Measurements are performed by stimulated Raman gain spectroscopy between 300 and 1000 K in a wide density range (from 0.2 to 11 amagat). All the observed spectral features are accurately described by a unified model recently proposed by two of the authors. This model accounts for a velocity-memory process, not restricted to the usual hard and soft limits. It also includes correlation between velocity- and phase-changing collisions. An exhaustive analysis of vario…
Local detection of the optical magnetic field in the near zone of dielectric samples
2000
International audience; We present a study of the influence of the probe composition on the formation of constant-height photon scanning tunneling microscope images when observing a dielectric sample. Dramatic effects due to the metallization of the tip are presented and discussed in detail. We show how the recorded images can look quite different when the probe is dielectric or coated with gold. Comparison with numerical calculations indicate that the experimental signals are of electric or magnetic nature depending on the composition of the tip. For well-defined conditions, gold-coated tips provide images of the distribution of the magnetic field intensity associated with the optical near…
Near-field control of optical bistability in a nanocavity
2009
Micro- and nanocavities allow for strong light confinement in very small volume [1]. They give opportunities for new experiments such as cavity quantum electrodynamics, waveguiding, light slowing or trapping…[2] The increase of the electromagnetic (EM) field in the cavity enhances the interaction between light and matter, resulting in the possible observation of nonlinear effects [3]. Several studies have recently been published on the observation and characterisation of nonlinear silicon cavities [4]. As a step further, we propose and demonstrate the feasibility of an innovative way to mechanically control the bistable operating regime of a nanovavity. Using a near-field tip, we switch the…
Dielectric-loaded surface plasmon-polariton waveguides at telecommunication wavelengths: Excitation and characterization
2008
International audience; The excitation and propagation of strongly confined surface plasmon-polariton (SPP) waveguide modes, supported by 500-nm-wide and 550-nm-high dielectric ridges fabricated on smooth gold films, are investigated at telecommunication wavelengths using a scanning near-field optical microscope. Different tapering structures for coupling of SPPs, excited at bare gold surfaces, into dielectric-loaded SPP waveguide (DLSPPW) modes are considered. The DLSPPW mode confinement and propagation loss are characterized. The DLSPPW mode propagation along an S bend having the smallest curvature radius of 2.48 mu m is shown, demonstrating the potential of DLSPPW technology for the real…
All-optical nonlinear simultaneous polarization and intensity regeneration of a 40-Gb/s telecommunication signal
2012
We experimentally report the simultaneous all-optical regeneration of the polarization state and the intensity profile of a 40 Gb/s Return-to-Zero telecommunication signal by means of Kerr effect occurring in a single segment of fiber.