Waveguide effect

W. H. Butler, X.-G. Zhang, D. M. C. Nicholson, T. C. Schulthess, and J. M. MacLaren, Giant Magnetoresistance from an Elecuon Waveguide Effect in Cobalt-Copper Multilayers , Physical Review Letters 76, pp.3216-3219, (1996). 

Absolute photoluminesccnce efficiency measurements in thin solid films are quite difficult, since light-trapping, waveguiding effects and, possibly, distributions in the emission dipole moments of individual chromophorcs modify the angular distribution of the emission. Dc Mello el al. ]126] have described an improved mclh-... 

Figure 22. Calculated waveguide effective index shift due to the presence of a 4 nm thick layer with refractive index n = 1.5 on top of the waveguide core. This layer is intended to emulate the the adsorption of a layer of large organic molecules. The index shift is shown for SOI and glass waveguides of varying core layer thickness. The uppermost layer is assumed to be water (n = 1.3). The inset shows an expanded view of the SOI data.

In this paper, we are interested in stmctures with n / An when nonlinear and waveguiding effects are comparable. For the estimation of the range of powers we are interested in, take into account that for the weakly-guiding stmcture Uj I / An k, nj/ / Ae = A. Then the relationship... 

Closely related to the technique described here are the experiments of Takenaka and Nakanaga (33a) using resonance Raman scattering and the excitation of Raman scattering in thin films by means of waveguide effects or resonance enhancement of the electric field, which occurs when the thin film is used as an optical... 

Lukosz W, Tiefenthaler K (1984) Directional switching in planar waveguides effected by adsorption-desorption processes. In Proceedings of 2nd european conference on integrated optics, Florence, Italy... 

These features of the Raman bands of the ZnO nanostructures can be extremely powerful for the in situ identification of orientation of ZnO nanostructures employed in a converse piezoelectric actuator directly in an assembled state [45]. While their study focused on ZnO nanostructures, the authors noted that the general features (Raman bands and the waveguiding effect) described are equally applicable to other wurtzite type nanostructures and the approach suggested might serve as a universal tool for the versatile characterization of GaN, ZnS, and CdSe from the wurtzite family, which are utilized for optoelectronics, lasing, and piezoelectricity. 

Figure 6.10 Schematic representation of the jet cell and the waveguide effect [6.118].

Ab Initio Calculations Single Molecular Conductance and Waveguide Effects... 

Nakamura, H. and Yamashita, K. (2008) Systematic study on quantum confinement and waveguide effects for elastic and inelastic currents in atomic gold wire. Nano Lett., 8, 6-12. 

Still relatively unexplored, but potentially a large application field of ordered mesoporous materials is optics and electronics. Marlow et al. succeeded in the synthesis of ordered mesoporous silica fibers doped with a rhodamin laser dye [38]. Upon laser irradiation the waveguide effect reported earlier [27] led to amplification by stimulated emission along the fiber axis. The light emitted from the ends of the fibers was spectrally narrowed and highly directional. The effect observed can be described as a mirrorless lasing which can be useful in the construction of optical circuits. 

Fig. 14.40 Graph of the sensitivity (ratio of the TM modes. Substrate index 1.46, waveguide change of waveguide effective index to change index 2.00 and cover layer index 1.333 calcu-in refractive index of cover layer) as a function lated for illumination at 660 nm. of waveguide thickness for the first four TE and...

H. Butt, Q. Dai, R. Rajesekharan, T.D. Wilkinson, G.A.J. Amaratunga, Plasmonic band gaps and waveguide effects in carbon nanotube arrays based metamaterials. ACS Nano 5, 9138-9143 (2011)... 

FIGURE 9 Schematic of a double heterostructure laser, (a) Band diagram under forward bias, (b) Refractive index profile and optical field distribution, (c) Waveguiding effect produced by total internal reflection and the index profile shown in (b). [After Kapon (1989).]... 

Low-dimensional crystals such as epitaxial needles and solution-grown platelets of TPCOs act as a microscale gain medium. The self-cavity and self-waveguiding effects of these crystals result in ASE in the wavelength region of the fluorescence band where the self-absorption loss is minimized. Furthermore, the uniaxial orientation of the TPCO molecules in these low-dimensional crystals promotes the stimulated emission process and enhances the polarized ASE. 

Ducting A change in typical propagation conditions caused by anomalous atmospheric conditions which result in a waveguide effect. 

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