Three-dimensional two-photon

Baldacchini, T., LaFratta, C. N., Fairer, R. A., Teich, M. C., Saleh, B. E. A., Naughton, M. J., and Fourkas, J. T., Acrylic-based resin with favorable properties for three-dimensional two-photon... 

Maruo S, hioue H (2006) Optically driven micropump produced by three-dimensional two-photon microfabrication. Appl Phys Lett 89(14) 144101... 

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. 

Therefore it is reasonable to prepare already the data acquisition for a three dimensional evaluation in cone-beam-technique by means of two-dimensional detectors. The system is already prepared to integrate a second detector- system for this purpose. An array of up to four flat panel detectors is foreseen. The detector- elements are based on amorphous silicon. Because of the high photon energy and the high dose rates special attention was necessary to protect the read-out electronics. Details of the detector arrangement and the software for reconstruction, visualisation and comparison between the CT results and CAD data are part of a separate paper during this conference [2]. 

There are differences between photons and phonons while the total number of photons in a cavity is infinite, the number of elastic modes m a finite solid is finite and equals 3N if there are N atoms in a three-dimensional solid. Furthennore, an elastic wave has tliree possible polarizations, two transverse and one longimdinal, in contrast to only... 

Bhawalkar J D, Swiatkiewicz J, Pan S J, Samarabandu J K, Liou W S, He G S, Berezney R, Cheng P C and Prasad P N 1996 Three-dimensional laser scanning two-photon fluorescence confocal microscopy of polymer materials using a new, efficient upconverting fluorophore Scanning 18 562-6... 

For the application of QDs to three-dimensional biological imaging, a large two-photon absorption cross section is required to avoid cell damage by light irradiation. For application to optoelectronics, QDs should have a large nonlinear refractive index as well as fast response. Two-photon absorption and the optical Kerr effect of QDs are third-order nonlinear optical effects, which can be evaluated from the third-order nonlinear susceptibility, or the nonlinear refractive index, y, and the nonlinear absorption coefficient, p. Experimentally, third-order nonlinear optical parameters have been examined by four-wave mixing and Z-scan experiments. 

Diaspro A, Robello M (2000) Two-photon excitation of fluorescence for three-dimensional optical imaging of biological structures. J Photochem Photobiol B 55 1-8... 

Cumpston BH, Ananthavel SP, Barlow S, Dyer DL, Ehrlich JE, Erskine LL, Heikal AA, Kuebler SM, Lee IS, McCord-Maughon D, Qin J, Rockel H, Rumi M, Wu XL, Marder SR, Perry JW (1999) Two-photon polymerization initiators for three-dimensional optical data storage and microfabrication. Nature 398 51-54... 

At present, most PET scanners can acquire in both a two-dimensional as well as a three-dimensional mode, whereas SPECT cameras measure in a three-dimensional mode. The physical property of the dual-positron gamma-rays emission lends itself to mathematical reconstruction algorithms to produce three-dimensional images in which the calculations are much closer to exact theoretical ones than those of SPECT. This is, in part, due to the two-photon as opposed to single-photon approach. PET can now achieve resolutions, for example in animal-dedicated scanners, in the order of 1 or 2 mm. The resolution is inherently limited theoretically only by the mean free path or distance in which the positron travels before it annihilates with an electron, e.g. those in biological water 2-8 mm. SPECT, although achieving millimeter resolution with the appropriate instrumentation, cannot quite achieve these levels. 

N. Moll, and G.-L. Bona, Comparison of three-dimensional photonic crystal slab waveguides with two-dimensional photonic crystal waveguides efficient butt coupling into these photonic crystal waveguides. Journal of Applied Physics 93, 4986-4991 (2003). 

Strickler JH, Wehh WW (1991) Three-dimensional optical data storage in refractive media by two-photon point excitation. Opt Lett 16 1780-1782... 

Maruo S, Nakamura O, KawataS (1997) Three-dimensional microfabrication with two-photon-ahsorhed photopolymerization. Opt Lett 22 132-134... 

Design and application of high-sensitivity two-photon initiators for three-dimensional microfabrication. Photochem J Photobiol A Chem 158(2-3) 163-170... 

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... 

We have also used the Eosin-triethanolamine system to design a two-photon system based on visible laser-induced photopolymerization followed by UV-induced crosslinking as a means of building a three-dimensional network structure aimed at three-dimensional imaging. The key to our design, shown in Scheme 4 below, is incorporation of an acrylate monomer... 

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