333 research outputs found
Optical isolation with nonlinear topological photonics
It is shown that the concept of topological phase transitions can be used to
design nonlinear photonic structures exhibiting power thresholds and
discontinuities in their transmittance. This provides a novel route to devising
nonlinear optical isolators. We study three representative designs: (i) a
waveguide array implementing a nonlinear 1D Su-Schrieffer-Heeger (SSH) model,
(ii) a waveguide array implementing a nonlinear 2D Haldane model, and (iii) a
2D lattice of coupled-ring waveguides. In the first two cases, we find a
correspondence between the topological transition of the underlying linear
lattice and the power threshold of the transmittance, and show that the
transmission behavior is attributable to the emergence of a self-induced
topological soliton. In the third case, we show that the topological transition
produces a discontinuity in the transmittance curve, which can be exploited to
achieve sharp jumps in the power-dependent isolation ratio.Comment: 11 pages, 7 figure
Solitons in magneto-optic waveguides with Kudryashovâs law nonlinear refractive index for coupled system of generalized nonlinear Schrödingerâs equation using modified extended mapping method
In this work, we investigate the optical solitons and other waves through magneto-optic waveguides with Kudryashovâs law of nonlinear refractive index in the presence of chromatic dispersion and Hamiltonian-type perturbation factors using the modified extended mapping approach. Many classifications of solutions are established like bright solitons, dark solitons, singular solitons, singular periodic wave solutions, exponential wave solutions, rational wave, solutions, Weierstrass elliptic doubly periodic solutions, and Jacobi elliptic function solutions. Some of the extracted solutions are described graphically to provide their physical understanding of the acquired solutions
Difference frequency generation by quasi-phase matching in periodically intermixed semiconductor superlattice waveguides
Wavelength conversion by difference frequency generation is demonstrated in domain-disordered quasi-phase-matched waveguides. The waveguide structure consisted of a GaAs/AlGaAs superlattice core that was periodically intermixed by ion implantation. For quasi-phase-matching periods of 3.0â3.8 μm, degeneracy pump wavelengths were found by second-harmonic generation experiments for fundamental wavelengths between 1520 and 1620 nm in both type-I and type-II configurations. In the difference frequency generation experiments, output powers up to 8.7 nW were generated for the type-I phase matching interaction and 1.9 nW for the type-II interaction. The conversion bandwidth was measured to be over 100 nm covering the C, L, and U optical communications bands, which agrees with predictions
Accelerated optical solitons in reorientational media with transverse invariance and longitudinally modulated birefringence
We demonstrate that reorientational spatial solitons can curve when propagating in a medium with engineered walk-off along the direction of propagation. In this regard, we employ nematic liquid crystals with molecular anchoring defined by electron-beam lithography and optic axis distribution modulated in the longitudinal direction only, keeping the transverse orientation constant. The experimental results are in remarkably good agreement with a simple modulation theory based on momentum conservation
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