Wave guiding properties

Semiconductor nano element devices show great promise, potentially outperforming standard electrical, opt-electrical, and sensor- etc. semiconductor devices. These devices can use certain nano element specific properties, 2-D, 1-D, or 0-D quantum confinement, flexibility in axial material variation due to less lattice match restrictions, antenna properties, ballistic transport, wave guiding properties etc. Furthermore, in order to design first rate semiconductor devices from nanoelements, transistors, light emitting diodes, semiconductor lasers, and sensors, and to fabricate efficient contacts, particularly with low access resistance, to such devices, the ability to dope and fabricate doped regions is cracial [66, 67]. 

Mathy A, Mathauer K, Wegner G and Bubeck C (1992) Preparation and wave-guide properties of polyglutamate Langmuir-Blodgett films, Thin Solid Films 215 98-102. 

With the advent of sophisticated techniques such as molecular beam epitaxy (MBE) and metal organic chemical vapor deposition (MCXTVD), synthesis of heterostructure such as multiple quantum wells or superlattices with precise interface layer down to one monolayer have been routinely possible. This not only allows modulation of electronic properties such as carrier confinement and concentration profile, but also optical confinement and wave guiding properties with appropriate choice of refractive indices of the materials. Such precise controls over the growth and material properties have opened the field of band gap engineering . 

Figure 15.17 Illustration of the assembly mechanism leading to the growth of PBG structures (i] Opened microchannel templates are immersed vertically in a suspension of silica microspheres. Upon evaporation, channels are selectively filled with particles that self-organize into crystalline 3D structures (li). Illustration of the wave-guiding properties of such opal channels is given in (ill) through an optical micrograph and reflectance/transmittance spectra. ...

From Snell s Law, sin(0j) m = sin(0j) nr. We have TIR when sin(Oj) > nr/rii, while we will have refraction and reflection when sin(0j) < nr/ni. In practical cases properties of light, such as phase, polarization and intensity, can be modulated inside the wave guide by a given measurand, which is interacting, for instance, with a CIM lying within the penetration depth for the evanescent field of the light localized near the external guide surface. 

From these results, As the particular tensor component of DAD molecular crystal is expected to be very high, more than 2-methyl-4-nitroaniline(MNA)(20), it would become one of the most suitable materials of highly efficient optical device for frequency doubler by using phase matching with optical wave guide. Electro-optical properties as well may be interesting. 

Nanoporous materials are of great interest for example for their photoluminescent properties (silicon) or possible use as templates (alumina). The types of synthesis of these materials are numerous and the etching/ anodization influences the results [27 - 29]. A detailed studied of Cherenkov radiation in nanoporous alumina membranes has been done which explains the existence of low energy peaks around 7-8 eV [30] (Figure 9 left). Whereas for a cylindrical hole in alumina the simulation does not show a peak, a cylindrical shell of alumina does. The Cherenkov radiation is confined in the shell, as in a wave guide, and a peak appears. If an effective... 

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