Photonic crystal

Equation (6.7) like equation (6.6) gives two possible solutions for (/ PH but this can be used in place of a second heavy atom derivative, to 

Recently the bond valence method (see Section 7.8) has been applied successfully to the discrimination between various cation bonding sites in protein crystals (see Bibliography for the reference). 

Photonic crystals are natural or artificial solids that are able to manipulate light in a predetermined fashion, rather as X-rays are manipulated by ordinary crystals. For this to be possible they must contain an array of scattering centres analogous to the atoms in ordinary crystals. Perhaps surprisingly, the diffraction phenomena are little different than that described for X-ray, electron and neutron diffraction, and the equations given above in this Chapter apply to photonic crystals as well as X-rays. 

The two aspects can be compared via Bragg s law, (Section 6.1). The position of a strongly diffracted X-ray beam from a crystal is given by  

Although the diffraction conditions are specified by the Bragg equation, because the diffraction takes place within a silica matrix, the real layer spacing, d nm, must be replaced by the optical thickness, [d, equal to nsd, where ns is the refractive index of the silica in opal, about 1.45. The correct equation to use for opal is thus  

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The effects of dispersion and birefringence on stellar interferometry will be discussed in Sections 17.2.3 and 17.2.4. New kind of fibres has been design to manage the dispersion properties using a silica / air structure. These fibres, so called Photonic Crystal Fibres, are very promising for many applications (Peyrilloux et al., 2002). 

Figure 3. Photonic Crystal Fibre (PCF). An air hole / silica arrangement allows to manage the dispersion properties.

Peyrilloux, A., Pagnoux, D., Reynaud, F, 2002, Evaluation of photonic crystal fiber potential for fibre linked version of stellar interferometers SPIE 4838, 1334... 

Blockstaller M., Kolb R., and Thomas E.L., Metallodielectric photonic crystals based on diblock copolymers, Adv. Mater., 13, 1783, 2001. 

Vlasov YuA, Luterova K, Pelant I, Honerlage B, Astratov VN (1997) Enhancement of optical gain of semiconductors embedded in three-dimensional photonic crystals. Appl Phys Lett 71 1616-1618... 

Rogach AL, Kotov NA, Koktysh DS, Ostrander W, Ragoisha GA (2000) Electrophoretic deposition of latex-based 3D colloidal photonic crystals A technique for rapid production of high-quality opals. Chem Mater 12 2721-2726... 

Braun PV, Wiltzius P (1999) Microporous materials. ElectrochemicaUy grown photonic crystals. Nature 402 603-604... 

Anisotropy is frequently observed in soft materials, but the symmetry of anisotropy is varying. Fibers and films show, in general, less complex anisotropy than ordinary or photonic crystals. 

Lanthanide-doped inverse photonic crystals have been reported.282 The lattices were prepared by infilling self-assembled polystyrene sphere templates with a mixture of zirconium alkoxide and europium at 450 °C, the polystyrene spheres were burnt out leaving hollow spheres of air, and the infilled material was converted to Zr02 Eu3+. The PL properties of the resulting photonic lattice were reported.282 The possibility of including phosphors into photonic lattices could lead to many... 

Knight, J. C., Arriaga, J., Birks, T. A., Ortigosa-Blanch, A., Wadsworth, W. J. and Russell, P. S. (2000). Anomalous dispersion in photonic crystal fiber. IEEE. Photon. Technol. Lett. 12, 807-9. 

Schreiber, T., Limpert, J., Zellmer, H., Tunnermann, A. and Hansen, K. P. (2003). High average power supercontinuum generation in photonic crystal fibers. Opt. Commun. 228, 71-8. 

Kudlinski, A., George, A. K., Knight, J. C., Rulkov, A. B., Popov, S. V. and Taylor, J. R. (2006). Zero-dispersion wavelength decreasing photonic crystal fibers for ultraviolet-extended supercontinuum generation. Opt. Express 14, 5715-22. 

Recently Hopman and al.15 applied a quasi one-dimensional photonic crystal (length 76 pm) for optical sensing. They measured the transmission spectrum as a function of the cladding refractive index. The cladding was varied using a liquid flow, of which the index was slowly varied over a small range (Figure 9). 

Figure 9. Cross-section of a refractive index sensor based on a quasi one-dimensional photonic crystal with grating period A = 190 nm. The top cladding over the grating is formed by a fluid contained in a cuvette that is sealed to the sensor chip.

Akahane Y., Asano T., Song B.S. and Noda S., High-Q photonic nanocavity in a two-dimensional photonic crystal, Nature 2003 425 944-947. 

SILAR has been used for the synthesis of CdS/ZnS coatings for CdSe quantum dots. The precursor solutions were prepared by dissolving CdO, ZnO, and S in oleic acid and octadecane. The final coating consisted of three layers of CdS and three additional layers of ZnS. The photonic band structure of the photonic crystal had a modifying influence on the photoluminescence of the embedded quantum dots.90... 

Fleischhaker, E Zentel, R. 2005. Photonic crystals from core-shell colloids with incorporated highly fluorescent quantum dots. Chem. Mater. 17 1346-1351. 

Fuertes, M. C. Lopez-Alcaraz, F. J. Marchi, M. C. Troiani, H. E. Luca, V. Miguez, H. Soler-Illia, G. 2007. Photonic crystals from ordered mesoporous thin-film functional building blocks. Adv. Fund. Mater. 17 1247-1254. 

Aoki, K. et al. 2003. Microassembly of semiconductor three-dimensional photonic crystals. Nature Mater. 2 117-121. 

Park, J. D. Lee, K. D. 2007. Method for manufacturing stamp for nanoimprint lithography having two-dimensional pattern of uniform size and shape, and method for photonic crystal using the same. LG Electronics Inc., S. Korea. 

The collection of chapters in this book represents the most recent global efforts in the research and development of photonic bio/chemical sensing structures. The photonic structures included in book are quite diversified, ranging from optical resonators and interferometers to photonic crystals and specially designed waveguides. For guidance, they are summarized as follows ... 

Bragg diffraction on crystalline colloidal arrays Photonic crystal material is composed of a crystalline colloidal array that diffracts light at wavelengths determined by the optical lattice spacing, which is affected by the presence of analyte 5,14,15... 

R. Hahn, P. Feisst, A. Lambrecht, A., Application of photonic crystals for gas detection and sensing, In Photonic Crystals Busch, K., Ed. Wiley VCH Verlag, Weinheim, Germany, 2004, 238 246... 

Arsenault, A. C. Kitaev, V. Manners, I. Ozin, G. A. Mihi, A. Miguez, H., Vapor swellable colloidal photonic crystals with pressure tunability, J. Mater. Chem. 2005, 15, 133 138... 

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