Arnaud Mussot

Impact of the longitudinal variations of the chromatic dispersion on the gain of fiber parametric amplifiers

We study experimentally the detrimental impact of longitudinal variations of chromatic dispersion on the gain of a broadband fiber optical parametric amplifier. Thanks to the optimization of the pump wavelength, a 3dB-gain bandwidth of 25nm is demonstrated using only 740mW pump power.

Non-destructive phase and intensity distributed measurements of the nonlinear stage of modulation instability in optical fibers

We report a novel experimental setup to perform distributed characterization in intensity and phase of the nonlinear stage of modulation instability by means of a non-invasive experimental setup : a heterodyne time domain reflectometer.

Geometric parametric instability in modulated parabolic graded-index fibers

We show that a periodic modulation of the diameter of a graded-index multimode fiber modifies the intrinsic self-imaging pattern, generating new spectral components in the geometric parametric instability gain spectrum.

Observation of period-doubling dynamics of modulation instability in uniform and dispersion oscillating fiber-ring cavities

We provide a direct observation of a period-doubling phenomenon associated to the modulation instability in both uniform and dispersion oscillating passive fiber ring cavities. This has been done by performing roundtrip-to-roundtrip measurements of the temporal pattern generated through the instability.

Versatile laser and optical amplifier for ultrafast imaging

Photonic technologies revolutionize optical imaging, from source generation to signal detection. Here we report MHz broadband swept sources for ultrafast imaging modalities. Their performance can be enhanced by broadband and sensitive fiber optical parametric amplifier.

Progress in Continuous-Wave Supercontinuum Generation

Supercontinuum (SC) light sources are nowadays a very common way to access a large span of wavelengths, usually ranging from the near ultraviolet (around 400 nm) to the infrared (around 2.4 μm). It corresponds to a range of interest for many applications in optics for measuring transmission, dispersion, or in biophotonics for achieving fluorescencemicroscopy, optical coherence tomography... Indeed these sources are really promising because they should allow to replace the N laser sources used in these experimental setups to access to all theses wavelengths by a single broad one and a spectral filtering apparatus. Most of these results have been obtained by using powerful pump lasers of several kilo-Watts peak power, operating from the femtosecond (Titane:Saphire) to the nanosecond regimes (Nd:YAG), launched in the low dispersion region of a microstructured optical fiber. Although these fibers are short enough (typically from 1 to 10 m) to neglect the linear absorption during the propagation of the pump, the spectral power density is relatively low (few hundreds of μw/nm)which could limit the implementation of SC sources inmany application devices. This is related to a technological limitation of the pump source because it is not easy to combine strong peak power and high average power. One of the simplest solutions to increase the the spectral power density of SC sources is to replace pulsed sources with continuous-wave (CW) light sources whose available average powers are much more important. Wewill see that the dynamics of SC formation is considerably different in this case, requiring to perform intensive numerical studies to optimize the fiber parameters. Indeed, longer fibers are required (from tens to hundreds of meters) which heightens sensitivity to fiber attenuation, namely of the OHpic absorption, that strongly impacts the soliton evolution. However extremely powerful SCs have been reported with more than 10 mW/nm of spectral power density. Furthermore, these pump sources are usually all-fiber that leads to a second advantage against most of pulsed SC because CW pump can be directly spliced on the PCF. It is also important to point out that these SC sources have different temporal properties than the ones of pulsed SCs. The first experimental demonstration of CW SC have been realized at the end of the nineties with a Raman laser launched in a standard telecommunication fiber. The spectral broadening was relatively restricted (around 200 nm) because it was mainly due to Raman effect Gonzalez-Herraez et al. (2003); Persephonis et al. (1996); Prabhu et al. (2000). A breakthrough was reached a few years later when stronger pump lasers (from more than one order of magnitude) based on Ytterbium doped fibers were combined with photonic crystal fibers 4

Influence of the phase modulation of the pump wave in fiber optical parametric amplifiers

We show analytically and numerically that phase modulation of the pump has a detrimental impact on the gain in fiber optical parametric amplifiers, which both depends on the modulator rise time and fiber dispersion slope.

Broadband and flat parametric gain with a single pump in a multi-section nonlinear fiber arrangement

Summary from only given. Parametric amplification appears now as a promising solution for fiber WDM systems and opens up a new means to cover actual and future telecommunications windows. Optical parametric amplifiers (OPA) can directly generate a broad and flat gain region by using two pump lasers or multiple fibers with different group-velocity dispersions. In this work, we propose and theoretically study multi-section OPA configurations based on four NLFs with different zero-dispersion wavelengths to achieve broadband and flat parametric gain.