Observation of optical event horizons in integrated nanophotonic waveguides
à 11h en salle C. Brot
The nonlinear interactions between solitons and weak dispersive waves have attracted a lot of attention in the scientific community for many years, particularly for their role played in the supercontinuum generation . Recently, it has been shown that, under some circumstances, some of these interactions can mimic the effects arising at the horizon of black and white holes . These so-called optical event horizons occur when a probe wave is unable to pass through an intense pump wave despite its different velocity. The intense pump induces a moving refractive index barrier, which in turn leads to a frequency conversion of the probe through a cross-phase modulation effect. Such interactions have been largely demonstrated in optical fibers [2, 3] for their numerous applications (e.g. efficient frequency converter, transistor-like functionalities) [5, 6] or their analogies with the general relativity . Recently, we have achieved the first demonstration of an optical event horizon in a nanophotonic waveguide . Thanks to the inherent high confinement in these structures, resulting in strong nonlinearities, the interactions take place on millimeter length scales using picojoule pump pulses. Finally, very recently, we have also observed an optical event horizon using cross-polarized waves in a birefringent nanophotonic waveguide, an effect that has only been considered in the context of photonic crystal fibers.
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6. C. Ciret, F. Leo, B. Kuyken, G. Roelkens and S.-P. Gorza, ”Observation of an optical event horizon in a silicon-on-insulator photonic wire waveguide,” Opt. Express 24, 114–124 (2016).
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