The dispersion relations, stability to propagation, absorption effects and Gaussian beam excitation of nonlinear TE waves guided by graded-index planar waveguides with both Kerr-law and saturable nonlinear cladding me...
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The dispersion relations, stability to propagation, absorption effects and Gaussian beam excitation of nonlinear TE waves guided by graded-index planar waveguides with both Kerr-law and saturable nonlinear cladding media are discussed numerically. The spatial soliton emission and the effects of linear absorption on spatial soliton emission in graded-index planar waveguides with Kerr-like nonlinear cover media are investigated by numerical techniques. The stationary field distribution and the guided wave power flow-effective mode index relationship are obtained using the finite element method. The propagation down the waveguide of nonlinear TE waves excited by a specific input beam is investigated numerically using the Crank-Nicolson finite-difference scheme combined with the Newton-Picard method for solving the corresponding system of nonlinear equations.
An improved method has been implemented to study the reflection of optical plane waves from anisotropic and absorbing films. The reflection from anisotropic nonabsorbing films and from isotropic nonabsorbing films can...
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An improved method has been implemented to study the reflection of optical plane waves from anisotropic and absorbing films. The reflection from anisotropic nonabsorbing films and from isotropic nonabsorbing films can be shown as some special cases. The method in this paper can be applied to almost all kinds of materials involved in optical films and integrated optics studies. Guided waves in the anisotropic and absorbing waveguides are determined, and the prism coupler method is employed to determine refractive indices and thickness of the anisotropic and absorbing films. The results show that when we only couple light beams into films with small effective indices, the effect of the absorption can be neglected.
We analyze the transmission of light through coupled-resonator opticalwaveguides in the form of evanescently coupled Fabry-Perot resonator arrays. We develop a transfer matrix method to calculate the amplitude and ph...
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We analyze the transmission of light through coupled-resonator opticalwaveguides in the form of evanescently coupled Fabry-Perot resonator arrays. We develop a transfer matrix method to calculate the amplitude and phase responses of the arrays. We also discuss the inclusion of optical gain in the system to compensate for losses in these structures. Owing to the compact length along the propagation direction in evanescently coupled arrays, large slowing factors of the order of 10(2)-10(3) can be achieved even with a weak index contrast of similar to 0.1%. The large slowing factor, coupled with weak index contrast, makes this structure a promising candidate for artificial slow light system. (c) 2007 optical Society of America
We present a detailed coupled-mode analysis of superimposed phase grating guided-wave structures for multibeam splitting (MBS) and wavelength demultiplexing (WDM) applications, taking into account the intergrating cou...
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We present a detailed coupled-mode analysis of superimposed phase grating guided-wave structures for multibeam splitting (MBS) and wavelength demultiplexing (WDM) applications, taking into account the intergrating coupling effects. The case of small angular separation between the output waves and the case of small wavelength separation between the spectral components of the input wave, which are of great importance for high fanout devices and have so far not been adequately treated, have been examined. For the MBS case (single-wavelength diffraction), critical parameters affecting the diffraction characteristics are found to be the relative index modulation between the gratings, the relative and absolute angular positions of the diffracted waves, the number of gratings, and the wavelength and polarization of the incident wave. For the WDM case (multiwavelength diffraction), wavelength separation between the spectral components of the incoming beam is shown to be an additional critical parameter, due to parasitic waves in undesired output channels. To obtain high-performance devices (high fanout density, high channel efficiencies, high angular and wavelength selectivities, and low cross talks between channels), the analysis suggests the use of long grating structures with large diffraction angles and gratings with close index modulations.
In this paper, we report on the development of the self-collimation phenomenon in photonic crystal structures for integrated optics applications. In addition, detailed numerical analysis, design procedures, fabricatio...
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In this paper, we report on the development of the self-collimation phenomenon in photonic crystal structures for integrated optics applications. In addition, detailed numerical analysis, design procedures, fabrication and characterization techniques are included. Applications presented in this paper include: channelless waveguiding, orthogonal bending of light, tunable beam splitter, all-optical analog-to-digital converter, reconfigurable optical switch, chemical/gas sensor and a three-dimensional optical interconnect bus.
A model is proposed for describing two-dimensional diffusion of Ti into an initially congruent LiNbO3 crystal under a Li-enriched atmosphere created by a mixed two-phase (Li3NbO4 and LiNbO3) powder at elevated tempera...
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A model is proposed for describing two-dimensional diffusion of Ti into an initially congruent LiNbO3 crystal under a Li-enriched atmosphere created by a mixed two-phase (Li3NbO4 and LiNbO3) powder at elevated temperature [vapor transport equilibration (VTE)]. The influence of VTE treatment on Ti diffusivity is considered in the model. To solve the model, four key input parameters including Li-concentration-dependent Li and Ti diffusivities and two switching times t(1) and t(2) were determined. Prior to solve the Ti-diffusion model, a one-dimensional VTE model is solved at first to obtain the dynamic Li2O concentration depth profile. Both the Li-diffusion and Ti-diffusion models were solved by using finite difference method. Based on secondary-ion-mass spectrometry analysis, the validity of the VTE and Ti-diffusion models as well as the numerical method employed are confirmed. After that, diffusion at 1100 degrees C of an 8-mu m-wide, 100-nm-thick Ti strip defined on the surface of a Z-cut or an X-cut substrate was simulated for the VTE duration up to 130 h. Based on the numerical results, the Ti-(Li-)diffusion characteristics are discussed in the aspects of (1) the relation of depth and width profile function of Ti concentration to the VTE duration, (2) the substrate cut effect on both the Ti and Li diffusions, (3) the relation of the 1/e Ti-concentration depth and half-width to the VTE duration, and (4) the VTE duration dependence of the mean [Li]/[Nb] ratio within the Ti-diffused layer. (c) 2007 American Institute of Physics.
A new coupled-mode formulation for parallel dielectric waveguides is presented by using a singular perturbation technique. The theory is applied to two parallel, planar dielectric waveguides and the coupled-mode equat...
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A new coupled-mode formulation for parallel dielectric waveguides is presented by using a singular perturbation technique. The theory is applied to two parallel, planar dielectric waveguides and the coupled-mode equations that are asymptotically correct are obtained.
A discussion of the evolution of the HE12 (LP02) field, and thus the role of the core in HE11-H12 (LP01-LP02) local-mode coupling for a tapered 'doubly-clad' lightguide as may be formed by the combination fini...
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A discussion of the evolution of the HE12 (LP02) field, and thus the role of the core in HE11-H12 (LP01-LP02) local-mode coupling for a tapered 'doubly-clad' lightguide as may be formed by the combination finite-cladding fibre and external medium (i.e. outer cladding) is presented. Consideration of more than one interface injects interesting novel features into the local-normal-mode viewpoint: examination of the HE12 lobe maximum and field evolution leads to the discovery of a core/cladding bounce phenomenon (related to an HE12 leaky-mode property) as well as an intriguing coupling phase dependence.
The Letter reports the first observation of waveguided, quasiphase-matched, parametric fluorescence at 1.2-2.5 mum at ambient temperature, using an 800 nm pump. Fluorescent powers of 10(-15)-10(-14) W were obtained fo...
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The Letter reports the first observation of waveguided, quasiphase-matched, parametric fluorescence at 1.2-2.5 mum at ambient temperature, using an 800 nm pump. Fluorescent powers of 10(-15)-10(-14) W were obtained for pump powers of 1-15 mW, an order of magnitude improvement over previous results.
Results on S-bend losses in fibre-compatible K+-Na+ ion-exchanged waveguides are presented. For the first time a distinction has been made between pure bend loss and transition loss. Experimental results are compared ...
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Results on S-bend losses in fibre-compatible K+-Na+ ion-exchanged waveguides are presented. For the first time a distinction has been made between pure bend loss and transition loss. Experimental results are compared to those of two theoretical models. Lateral offsets in waveguide junctions to reduce transition loss are investigated. This set of results can be used to optimise the design of S-bends with respect to length and loss.
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