Search results for " optical fiber"
showing 10 items of 327 documents
In-fiber time-resolved acousto-optics
2014
Time-resolved in-fiber acousto-optics permit the measurement of sub-ppm perturbations of the modal dispersion curves along sections of fiber exceeding 1 m long, with a spatial resolution in the order of few cm.
Dispersion induced effects of high-order optical sidebands in the performance of millimeter-wave fiber-optic links
2006
In this paper, chirped fiber Bragg gratings (CFBGs) are proposed as signal-phase controllers for microwave-photonic wireless downstream fiber links. The effect of high-order modulation optical sidebands that disturbs the output mm-wave signal due to the chromatic dispersion induced by the gratings is studied theoretically and experimentally. The 1st and 2nd mm-wave harmonics of the output signal have been measured for conventional intensity modulation and for intensity modulation with optical carrier suppression. In the last case, data transmission at 2.5 Gb/s is demonstrated through a chirped grating of 280 ps/nm dispersion in a 40-GHz modulated link.
Extremely efficient evaluation of chromatic dispersion in realistic photonic crystal fibers
2004
We present a fast and accurate procedure for the evaluation of chromatic dispersion in photonic crystal fibers. It combines an iterative Fourier technique to compute the propagation constant at any fixed wavelength and an analytical approach to calculate its derivatives.
Suppression of pulse pedestal using nonlinear optical loop mirrors in grating-compensated dispersion-managed fiber transmission systems
2006
Pulse pedestal suppression by nonlinear optical loop mirrors is utilized to reduce the intersymbol interference caused by the group delay ripples of a real grating profile in dispersion-managed communication systems compensated by chirped fiber gratings.
Seeded intermodal four-wave mixing in a highly multimode fiber
2018
International audience; We experimentally and theoretically investigate the process of seeded intermodal four-wave mixing in a graded-index multimode fiber, pumped in the normal dispersion regime. By using a fiber with a 100-mu m core diameter, we generate a parametric sideband in the C-band (1530-1565 nm), hence allowing the use of an erbium-based laser to seed the mixing process. To limit nonlinear coupling between the pump and the seed to low-order fiber modes, the waist diameter of the pump beam is properly adjusted. We observe that the superimposed seed stimulates the generation of new spectral sidebands. A detailed characterization of the spectral and spatial properties of these sideb…
Widely Tunable Polarization Modulation Instability in D2O-Filled Microstructured Optical Fiber
2021
Polarization modulation instability (PMI) is a nonlinear effect in which two pump photons with identical polarization propagating in a nonlinear medium give rise to two new photons of different frequency and orthogonal polarization with respect to the pump photons [1] . In this work, we report the experimental demonstration of broad spectral tuning of PMI generated in solid-core microstructured optical fibers (MOF) that were previously infiltrated with heavy water (D 2 O). MOFs were designed and fabricated with the appropriate dispersion characteristics to produce widely spaced PMI spectral bands when they were filled with D 2 O and pumped at 1064 nm. Heavy water was chosen due to suitable …
Low loss microstructured chalcogenide fibers for large non linear effects at 1995 nm
2010
International audience; Microstructured optical fibers (MOFs) are traditionally prepared using the stack and draw technique. In order to avoid the interfaces problems observed in chalcogenide glasses, we have developed a new casting method to prepare the chalcogenide preform. This method allows to reach optical losses around 0.4 dB/m at 1.55 µm and less than 0.05 dB/m in the mid IR. Various As(38)Se(62) chalcogenide microstructured fibers have been prepared in order to combine large non linear index of these glasses with the mode control offered by MOF structures. Small core fibers have been drawn to enhance the non linearities. In one of these, three Stokes order have been generated by Ram…
Chalcogenide Microstructured Fibers for Infrared Systems, Elaboration, Modelization, and Characterization
2009
special issue " Fiber Optic Research in France " (Part III of III); International audience; Chalcogenide fibers present numerous possible applications in the IR field. For many applications, single mode fibers must be obtained. An original way is the realization of microstructured optical fibers (MOFs) with solid core. These fibers present a broad range of optical properties thanks to the high number of freedom degrees of their geometrical structure. In this context, we have developed MOFs for near and mid IR transmission with different geometries and properties such as multimode or endless single-mode operation, small or large mode area fibers. We have also investigated numerically the mai…
All-optical nonlinear processing of both polarization state and intensity profile for 40 Gbit/s regeneration applications
2011
International audience; In this paper, we report all-optical regeneration of the state of polarization of a 40-Gbit/s return-to-zero telecommunication signal as well as its temporal intensity profile and average power thanks to an easy-to-implement, all-fibered device. In particular, we experimentally demonstrate that it is possible to obtain simultaneously polarization stabilization and intensity profile regeneration of a degraded light beam thanks to the combined effects of counterpropagating four-wave mixing, self-phase modulation and normal chromatic dispersion taking place in a single segment of optical fiber. All-optical regeneration is confirmed by means of polarization and bit-error…
Theoretical study of cascade laser in erbium-doped chalcogenide glass fibers
2010
International audience; A theoretical investigation of an innovative cascade laser source is performed. The main goal of the work is the design of a continuous-wave (CW) photonic crystal fiber (PCF) laser, based on an erbium-doped chalcogenide glass. Due to the comparable lifetimes of the 4I13/2, 4I11/2 and 4I9/2 erbium energy levels, the simultaneous emissions at the wavelengths close to 2.7 μm and 4.5 μm are obtained with a pump wavelength close to 806 nm (direct pumping into the level 4I9/2). This scheme could be useful to develop high efficiency, high beam-quality and compact Near-IR and Mid-IR oscillators with single-mode output for applications not only in surgery but also in spectros…