1,721,050 research outputs found
Tunable wavelength-selective add-drop in liquid crystals on a silicon microresonator
No full textWe propose and numerically investigate a tunable add-drop consisting of an optical disk microresonator embedded in nematic liquid crystals. The electro-optic cladding enables tunability via an external low-frequency voltage. All loss mechanisms as well as the features of the tunable filter are accounted for via a full-dimensional (3D + time) parallel Finite Difference Time Domain code. (C) 2007 Elsevier B.V. All rights reserved
Spatial optical solitons in nonlinearly coupled lithium niobate waveguides
No full textWe numerically investigate a novel type of quadratic spatial solitons in the system of surface and buried planar waveguides obtained via direct- and reverse-proton exchange in z-cut lithium niobate, respectively, and coupled by the second-order susceptibility. Through frequency doubling, transverse-electric and transverse-magnetic modes lock into a 1 + 1D solitary wave encompassing orthogonal field components at the two harmonic wavelengths. The phase matching scheme leads to a wavelength-comb filter with adjustable linewidths
Photonic crystal wires for optical parametric oscillators in isotropic media
No full textWe investigate four wave mixing in photonic crystal wire microresonators realized in an isotropic medium. One-dimensional optical parametric oscillators are numerically analyzed by solving Maxwell's equations in all dimensions and including material dispersion as well as nonlinear polarization
Three-dimensional superprism effect in photonic-crystal slabs
No full textThis paper presents a numerical study of the super-prism effect in photonic-crystal (PC) slabs. A fully vectorial three-dimensional time-domain code allows to simulate, with virtually no approximations, the role of the sample finiteness in the dispersive response of the frequency-banded structure. Out-of-plane coupling and transmission of, the device are investigated
Frequency generation within the forbidden band gap: All optical Rabi-like splitting in photonic crystals and microcavities
No full textBased on three-dimensional time domain numerical simulations of the nonlinear dispersive Maxwell equations, we find evidence of all optical splitting of defect states in a photonic band gap structure. The result is analogous to the well known Rabi splitting and optical nutation in atomic two-level systems, and can be used for controlled in-gap generation of optical frequencies. Photon-echo-like behavior and third harmonic generation are also investigated
Wavelength shifting in photonic bandgap microcavities with isotropic media
No full textBy coupled mode theory in the time domain and a finite-difference time-domain code, we investigate wavelength shifting and frequency conversion via four-wave mixing inside a photonic crystal wire in an isotropic Kerr material. The three-dimensional time-resolved analysis yields ultrafast and all-optically tunable frequency conversion of a signal/channel about the pump frequency
Wavelength shifting in photonic bandgap microcavities with isotropic media
No full textBy coupled mode theory in the time domain and a finite-difference time-domain code, we investigate wavelength shifting and frequency conversion via four-wave mixing inside a photonic crystal wire in an isotropic Kerr material. The three-dimensional time-resolved analysis yields ultrafast and all-optically tunable frequency conversion of a signal/channel about the pump frequency. (C) 2004 American Institute of Physics
Parametric oscillations in photonic crystal slabs 3-D time-domain analysis
No full textSlab waveguides with a two-dimensional periodic distribution of the refractive index are proposed and investigated as optical microcavities for efficient parametric oscillations through four-wave mixing in isotropic materials. We carry out a case study based on the complete solution of three-dimensional Maxwell equations, including material dispersion and cubic nonlinear response
Tunneling Mediated by 2D + 1 Conical Waves in a 1D Lattice
No full textThe propagation of 2D+1 wave packets in 1D band gap systems shows that the interplay of periodicity and nonlinearity leads to the spontaneous formation of fast and slow conical localized waves. Such nonlinear tunneling has features that differ on the two edges of the band gap and it is characterized by the competition of bullets and nonlinear X waves
Frequency generation within the forbidden band gap: All optical Rabi-like splitting in photonic crystals and microcavities
No full textBased on three-dimensional time domain numerical simulations of the nonlinear dispersive Maxwell equations, we find evidence of all optical splitting of defect states in a photonic band gap structure. The result is analogous to the well known Rabi splitting and optical nutation in atomic two-level systems, and can be used for controlled in-gap generation of optical frequencies. Photon-echo-like behavior and third harmonic generation are also investigated
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