Search results for "fiber"

Spectral incoherent solitons

2009

Solitons have been usually considered as inherently coherent localized structures and the discovery of incoherent optical solitons has represented a significant progress [1]. As occurs for standard coherent solitons, incoherent solitons are characterized by a confinement of the field in the spatial or in the temporal domain. We introduce here a novel type of incoherent solitons that are neither spatial nor temporal, i.e., the incoherent field does not exhibit any confinement in the spatiotemporal domain; however, the uncorrelated frequency components that constitute the incoherent field exhibit a localized soliton behavior in the frequency domain [2].

Duty-ratio control of Nonlinear phase noise in dispersion-managed WDM transmissions using RZ-DPSK modulation at 10 Gb/s

2006

International audience; The authors compare analytical and numerical estimates, showing that the nonlinear phase noise of short optical pulses associated with the coupling between amplified spontaneous emission noise and fiber nonlinearity may be controlled by adjusting the duty cycle of the return-to-zero (RZ) signal modulation format. The impact of this effect in the optimization of the performance of 10-Gb/s dispersion-managed wavelength division multiplexed (WDM) systems using RZ-differential phase-shift keying (DPSK) modulation is discussed. By extensive numerical simulations, it is shown that the transmission quality of ultradense WDM systems using the RZ-DPSK modulation format may be…

Analytical description of the transverse Anderson localization of light

2017

VSOP monitoring of the quasar 1928+738

2000

Abstract In the paper we describe the first results from a campaign to monitor the relatively low redshift (z=0.3) circumpolar superluminal quasar 1928+738 with VSOP. The three epochs of data that we have analyzed show that there have been substantial structural changes in this source near the core on the time-scale of a few months.

Variable delay line for phased-array antenna based on a chirped fiber grating

2000

We present a theoretical and experimental analysis of the performance of phased-array antennas steered by a single chirped fiber grating. Two approaches consisting of conventional and single-sideband (SSB) modulation techniques of the optical signal are presented in order to compare their performance and suitability for beamforming applications in microwave antennas. By using a 40-cm-long chirped grating, we measure the phase and amplitude response and calculate the corresponding radiation patterns to demonstrate wide-band operation and continuous spatial scanning properties of both configurations. SSB modulation Is presented as a real alternative to the first one offering broader operation…

Bloch wave theory of modulational polarization instabilities in birefringent optical fibers

1997

The modulational instability gain spectra, of an arbitrarily polarized intense pump wave that experiences periodic nonlinear polarization rotation in a birefringent optical fiber, are derived by Floquet analysis. The predictions of the linearized analysis are confirmed by numerical simulations of the coupled nonlinear Schr\"odinger equations.

Modulational instability processes in optical isotropic fibers under dual- frequency circular polarization pumping

2002

Experiments are presented showing that, under dual-frequency, circular polarization pumping, host modulational instability processes can be generated in a single-mode isotropic fiber by careful tuning of the frequency spacing between the pumps.

Generation of High-Repetition-Rate Dark Soliton Trains and Frequency Conversion in Optical Fibers

1998

Induced modurational polarization instability in birefringent fibers leads to trains of dark soliton-like pulses. Optimal large-signal cw and soliton frequency conversion is also analysed.

Manakov Polarization Modulation Instability in Normal Dispersion Optical Fiber

2014

We observed polarization modulation instability in the normal dispersion regime of randomly birefringent multi-km telecom optical fiber. The instability is pumped by two wavelength multiplexed and orthogonally polarized intense continuous lasers.

Polarization properties of a fiber optic loop mirror

2021

Abstract In this work, we present the spectral polarization properties of a fiber optic loop mirror (FOLM) which includes a 50/50 coupler and 25-cm long highly birefringent (hi-bi) fiber. The modulation depth of the reflection/transmission spectra can be adjusted by twisting the hi-bi fiber at the splices by means of two azimuth rotators (AR). The results show that the polarization properties of the reflection strongly depends on the angle rotation. We found that it is possible to obtain reflection spectral polarization independence for any modulation depth with the proper parameters. The experimental behavior was confirmed by numerical simulations based on the Jones matrix formulation.