Three-dimensional structure, photonic

In traditional Fan-Beam CT the radiation emitted from the X-ray tube is collimated to a planar fan, and so most of the intensity is wasted in the collimator blades (Fig. 2a). Cone-Beam CT, where the X-rays not only diverge in the horizontal, but also in the vertical direction, allows to use nearly the whole emitted beam-profile and so makes best use of the available LINAC photon flux (Fig. 2b). So fast scanning of the samples three-dimensional structure is possible. For Cone-Beam 3D-reconstruction special algorithms, taking in consideration the vertical beam divergence of the rays, were developed. 

M. Paulus, and O.J.F. Martin, A fully vectorial technique for scattering and propagation in three-dimensional stratified photonic structures. Optical and Quantum Electronics 33, 315-325 (2001). 

WitzgallG, Vrijen R, Yablonovitch E, Doan V, Schwartz B (1998) Single-shot two-photon exposure of commercial photoresist for the production of three-dimensional structures. Opt Lett 23 1745-1747... 

Optical activity in solution, unlike the same effect in crystals, is an isotropic effect. This interaction between a polarized photon and a molecule therefore implicates a chiral factor that is independent of direction, such as the molecular wave function, and in particular, its complex phase. It is a non-classical factor and hence cannot be attributed directly to a classical three-dimensional structure. In a crystal where optical activity arises from three-dimensional... 

Figure 3.74. Three-dimensional microstructures (photonic band-gap structure (a), magnified top view of the photonic band-gap material (b), tapered waveguide structure (c), cantilevers (d)) obtained by TP initiated polymerization. (From Ref. [134] with permission of Macmillan Magazines.)...

Since two photons are required to initiate the polymerisation, curing will only take place in the focal point of the laser [i.e. where the concentration of photons is the highest]. The microscope objective used to focus the laser beam can be moved relative to the sample. After removal of the uncured material, complex three-dimensional structures can be achieved via direct laser writing [127, 149]. Interestingly, biodegradable polyester oligomers have... 

Two-photon-initiated polymerization (TPIP) can easily produce three-dimensional holographic pattern. The scheme of TPIP is shown in Figure 5.22. Areas encountering double beams of 745 nm (near-infrared laser) are polymerized by two photons. Scanning double beams produce a three-dimensional structure. Kondo et al. reported on a two-photon-initiated polymerization system. A composite of the TPIP is shown in Figure 5.23. 

For demonstrative purposes, multilayer assanblies were constructed by placing an uncoated glass cover slip between two cover slips coated with patterned photosensitive films, with the coated sides against the middle cover slip late 2). Three-dimensional two-photon fluorescence imaging was poformed on the multilayer structures. 

Chigrin D.N., Lavrinenko A.V.,Yarotsky D.A.,Gaponenko S.V. OhsCTvation of total omnidirectional reflection from a one-dimensional dielectric lattice. Appl. Phys. A 1999 68 25-28 Divliansky I., Mayer T.S., HoUiday K.S., Crespi V.H. Fahrication of three-dimensional polymer photonic crystal structures using single diffraction element interference. Appl. Phys. Lett. 2003 82 1667-1669... 

Fan S., Villeneuve P.R., Meade R.D., Joannopoulos J.D. Design of three-dimensional photonic crystals at submicron lengthscale. Appl. Phys. Lett. 1994 65 1466-1468 Fink Y., Winn J.N., Fan S., Chen C., Michel J., Joannopoulos J.D., Thomas E.L. A dielectric omnidirectional reflector. Science 1998 282 1679-1682 Fukuda K., Sun H., Matsuo S., Misawa H. Self-organizing three-dimensional colloidal photonic crystal structure with augmented dielectric contrast. Jpn. J. Appl. Phys. 1998 37 L508-L511... 

Ye Y.H., LeBlanc F., Hache A., Truong V.V. Self-assembling three-dimensional colloidal photonic crystals structure with high crystalline quality. Appl. Phys. Lett. 2001 78 52-54 Yoshinaga K., Chiyoda M., Ishiki H., Okubo T. Colloidal crystallization of monodisperse and polymer-modified colloidal silica in organic solvents. Colloids Surfaces A Physicochem. Eng. Aspects 2002 204 285-293... 

Duan, X.M., Sun, H.B., Kaneko, K and Kawata, S. (2004) Two-photon polymerization of metal ions doped acrylate monomers and oligomers for three-dimensional structure fabrication. Thin Solid Films, 453, 518—521. 

Jia, B., Buso, D., van Embden, J., Li, J and Gu, M. (2010) Highly non-linear quantum dot doped nanocomposites for functional three-dimensional structures generated by two-photon polymerization. Adv. Mater., 22, 2463-2467. 

In the first stages of photosynthesis carried out in proteins such as bacterial reaction centers (RCs) the energy of an absorbed photon is used to initiate a series of intra-protein electron transfers. These reactions have been well characterized (see reference I for a review). One important consequence of the resulting charge separation is proton uptake from the interior of the cell. The stoichiometry of proton uptake on formation of different redox states as a function of pH has been described in detail. More recent studies have monitored the influence of specific amino acids on proton uptake stoichiometry and kinetics. " It is of interest to understand how the RCs three dimensional structure yields the observed coupling of electron and proton transfers. 

Tao R and Xiao D. 2002. Three-dimensional dielectric photonic crystals of body-centered-tetragonal lattice structure. Applied Physics Letters 80 4702-4704. 

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