Incoherent white-light solitons in nonlinear periodic lattices

Abstract

We predict the existence of lattice solitons made of incoherent white light: lattice solitons made of light originating from an ordinary incandescent light bulb. We find that the intensity structure and spatial power spectra associated with different temporal frequency constituents of incoherent white-light lattice solitons (IWLLSs) arrange themselves in a characteristic fashion, with the intensity structure more localized at higher frequencies, and the spatial power spectrum more localized at lower frequencies; the spatial correlation distance is larger at lower frequency constituents of IWLLSs. This characteristic shape of incoherent white-light lattice solitons reflects the fact that diffraction is stronger for lower temporal frequency constituents, while higher frequencies experience stronger effective nonlinearity and deeper lattice structure.

Polychromatic nonlinear surface modes generated by supercontinuum light

“…We study propagation of polychromatic light in an array of coupled optical waveguides created in a LiNbO 3 substrate, where the formation of monochromatic surface solitons due to photorefractive nonlinear response was recently demonstrated in experiment [5,6]. Photorefractive nonlinearity is based on a relatively slow charge accumulation, and therefore the induced refractive index can be defined by the time-averaged light intensity of different spectral components [8,9,10]. We consider an optical source with the high degree of spatial coherence, such as supercontinuum light generated in photonic-crystal fibers [11,12].…”

Incoherent modulation instability in a nonlinear photonic lattice

“…We envision several further research themes following our current study. Recent studies of incoherent white-light solitons in nonlinear photonic lattices [29] suggest that MI in photonic lattices is possible with incoherent white light [6,7] as well. It would be interesting to see whether all frequencies would behave collectively, as they do in a homogeneous medium […”

“…Our current study of incoherent lattice MI combines the phenomenon of coherent MI in ("discrete") periodic nonlinear systems [14,16,17,18,19,20,21], and that of incoherent MI in homogeneous nonlinear systems [2,3,4,5,6,7,8,9,10,11]. This analysis draws upon recent studies of partially coherent wave dynamics in noninstantaneous nonlinear photonic lattices [22,23,24,25,26,27,28,29], including the prediction [22] and observation [23] of random-phase lattice solitons, and the possibility of Brillouin-zone (BZ) spectroscopy [24] with incoherent light (see Ref. [25] for a review of the topic).…”

<title>Optical lattices as nonlinear photonic crystals</title>

“…11,51 A solution to counteract the strong dispersion of periodic structures can be achieved by employing nonlinear self-action effects. Recent theoretical predictions 52,53 show that optical nonlinearity can be successfully used to control the dispersion and spatial propagation of polychromatic light. To demonstrate experimentally such simultaneous spatio-spectral control we employed supercontinuum generation 5 from 150 fs pulses in a highly nonlinear photonic crystal fiber [see Fig.…”