Search results for "Physics::Optics"
showing 10 items of 1958 documents
Surface plasmon routing along right angle bent metal strips
2005
International audience; An efficient routing of surface plasmon polaritons (SPP) is of fundamental importance in the development of SPP-based photonics. This paper reports that microgratings acting as Bragg mirrors can guide SPP along metal stripes waveguides featuring 90 degrees bents. The measurement of the mirrors efficiency, performed by means of photon scanning tunneling microscopy, shows that bent losses as low as 1.9 dB can be achieved. Finally, we demonstrate operating SPP beamsplitters obtained by an appropriate design of the Bragg mirrors constituting elements. (c) 2005 American Institute of Physics.
Temporal analogue of the Fresnel diffraction by a phase plate in linear and nonlinear optical fibers
2021
The analogy existing between spatial and temporal optics has motivated many studies to interpret spatial phenomena in the domain of ultrafast optics [1] . Indeed, dispersion and one-dimensional diffraction may share the same mathematical formalism. Temporal analogues of common optical systems have been proposed such as lenses, imaging systems, diffraction gratings, which opens up a whole range of new possibilities for ultrafast photonics.
Generation of aperiodic picosecond pulses sequences from incoherent optical waves
2007
We present an original method to generate optical pulses trains with random time-interval values from incoherent broadband sources. Our technique relies on the remarkable properties of a line made of cascaded SPM-based optical regenerators.
Spatio-temporal beam dynamics in multimode nonlinear optical fibers
2017
We overview recent advances in the spatio-temporal nonlinear dynamics of optical pulses propagating in multimode optical fibers. The Kerr effect leads to spatial beam self-cleaning in a graded-index multimode optical fiber, followed by sideband series generation spanning multiple octaves. Effectively single mode supercontinuum spanning from the visible to the mid-infrared was also demonstrated. Enhancement of Kerr beam self-cleaning was observed in active fiber with quasi-step index profile. Moreover, mutual self-cleaning was recently reported for both the fundamental and the second harmonic beams in optically poled multimode fibers with cubic and quadratic nonlinearity.
Nonlinear spatial self-cleaning in multimode amplifying fiber and fiber laser cavity
2017
During the last years, multimode fibers (MMFs) were used as an experimental platform for the observation of complex nonlinear propagation phenomena, thanks to their additional spatiotemporal degrees of freedom with respect to single mode fibers. Multimode solitons [1], geometric parametric instability [2], self-induced beam cleaning (SBC) [3] and supercontinuum generation have been reported [4]. In all of these situations considered so far the MMFs were standard graded-index fibers: the intermodal interactions took place in a conservative system (propagation losses were negligible). In this work we have experimentally investigated the Kerr SBC in three dissipative systems: a MMF with signif…
Cascaded intermodal four-wave mixing in a few-mode fiber
2019
During the last few years, intensive works on multimode fibers allowed for the observation of a series of complex and novel nonlinear spatiotemporal phenomena such as: multimode solitons, geometric parametric instability, supercontinuum generation, and self-induced beam cleaning [1-4]. Among these phenomena, intermodal four-wave mixing (IMFWM) demonstrated larger frequency shifts in comparison with single-mode fibers. In this work, we studied IMFWM in a few-mode graded-index fiber (GRIN-FMF) pumped in the normal dispersion regime at 1064 nm. We report parametric sidebands detuned by hundreds of THz from the pump.
Polarization control in spun and telecommunication optical fibers
2011
International audience; We consider the counterpropagating interaction of a signal and a pump beam in a spun fiber and in a randomly birefringent fiber, the latter being relevant to optical telecommunication systems. On the basis of a geometrical analysis of the Hamiltonian singularities of the system, we provide a complete understanding of the phenomenon of polarization attraction in these two systems, which allows to achieve a control of the polarization state of the signal beam by adjusting the polarization of the pump. In spun fibers, all polarization states of the signal beam are attracted toward a specific line of polarization states on the Poincaré sphere, whose characteristics are d…
Gain sideband splitting in dispersion oscillating fibers
2014
International audience; We analyze the modulation instability spectrum in a varying dispersion optical fiber as a function of the dispersion oscillation amplitude, and predict a novel sideband splitting into different sub-sidebands for relatively large dispersion oscillations
Nonlinear optical fiber polarization tracking at 200 krad/s
2011
International audience; We demonstrate endless nonlinear polarization stabilization with a standard telecom fiber at a tracking speed of 200 krads/s. We provide a simple analytical estimate for the response time of nonlinear polarization control
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 …