RESUMEN
We report the observation of modulation instability (MI) in the mid-infrared (mid-IR) spectral region by pumping a hybrid polymer-chalcogenide optical microwire with a femtosecond optical parametric oscillator operating at 2.6 µm. It is further shown that this MI occurs in the normal dispersion regime through negative fourth-order dispersion and leads to far-detuned parametric frequency conversion at 2 and 3.5 µm, despite the presence of a strong absorption band around 2.8 µm. Stochastic nonlinear Schrödinger equation simulations of mid-IR MI are in excellent agreement with experiments.
RESUMEN
We report control of the spectral and noise properties of spontaneous modulation instability (MI) in optical fiber using an incoherent seed with power at the 10(-6) level relative to the pump. We sweep the seed wavelength across the MI gain band, and observe significant enhancement of MI bandwidth and improvement in the signal-to-noise ratio as the seed coincides with the MI gain peak. We also vary the seed bandwidth and find a reduced effect on the MI spectrum as the seed coherence decreases. Stochastic nonlinear Schrödinger equation simulations of spectral and noise properties are in excellent agreement with experiment.
