| 1. |
- Junique, Stephane, et al.
(författare)
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Large–area, three–state, binary amplitude and binary phase vertical–cavity multiple quantum well electroabsorption modulator
- 2007
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Ingår i: Optics Express. - 1094-4087. ; 15:14, s. 8566-8575
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Tidskriftsartikel (refereegranskat)abstract
- We present the design and characterization of a large optical modulator array based on GaAs multiple quantum wells for amplitude and phase modulation. The device shows two high-reflectance states with a phase difference close to 180 degrees for use as a binary phase modulator. It also shows a third, low-reflectance state for use as an amplitude modulator. It is segmented into 64 pixels in a single row, giving an active area of 2mm x 5mm. We discuss the device performance as a ternary binary amplitude and binary phase modulator, including contrast ratio and uniformity, and show that a voltage swing of only 5V is needed to drive it.
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| 2. |
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| 3. |
- Qinlu, Lin, et al.
(författare)
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Influence of amphiphilic structures on the stability of polyphenols with different hydrophobicity
- 2007
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Ingår i: Science in China. Series B: Chemistry. - : Springer Science and Business Media LLC. - 1006-9291 .- 1862-2771. ; 50:1, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- Autooxidation of five polyphenols representing range of different hydrophobicities (catechin gallate (CG), (-) catechin((-)C), epicatechin (EC), epigallocatechin gallate (EGCG) and epigallocatechin (EGC)) in three different aqueous solutions: molecular solution, micellar solution (Tween-20) and liposomal dispersion (soybean lecithin) was monitored by HPLC. The rate of oxidation of the five polyphenols was higher at pH 4.5 than at pH 3.5. Compared with the control, addition of Tween-20 (micellar structure) and lecithin (liposomal structure) significantly decreased the degradation of polyphenols. In the presence of lecithin the autooxidation of all the five polyphenols was slower than in the presence of Tween-20. The effective protection of the colloidal structures was compared with the hydrophobicity of the polyphenols estimated from the partitioning between octanol and water. The protection from oxidation in the presence of the colloidal structures (micellar or liposomal) increased with increasing partitioning of a polyphenol towards the hydrophobic environment. The protecting effect of the colloidal structures was more effective at pH 4.5 than at pH 3.5.
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| 4. |
- Sauge, Sebastien, et al.
(författare)
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Quantum communication in optical networks : an overview and selected recent results
- 2007
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Ingår i: ICTON 2007. - 9781424412488 ; , s. 30-33
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Konferensbidrag (refereegranskat)abstract
- We discuss recent work in quantum communication, and in some details present a bright, narrowband, portable, quasi-phase-matched two-crystal source generating polarization-entangled photon pairs at 809 nm and 1555 nm. We also show how the single-photon quantum channel at 1555 nm and a classical synchronization signal gating the single photon detector at the receiving side can be multiplexed in the same optical fiber of length 27 km by means of wavelength division multiplexers (WDM) having 100 GHz (0.8 nm) spacing between channels. This illustrates bow single-photon quantum communication applications is compatible with current high-speed optical networks.
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| 5. |
- Wang, Qin, et al.
(författare)
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Performance enhancement of a decoy-state quantum key distribution using a conditionally prepared down-conversion source in the Poisson distribution
- 2007
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 76:1
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Tidskriftsartikel (refereegranskat)abstract
- We study the behavior of decoy-state quantum key distribution systems using a conditionally prepared down-conversion source, analyzing such a source running in a mode of operation with either a thermal photon number distribution or a Poisson photon number distribution. By comparing both modes of operations to the three-intensity proposal of Wang , to the one-intensity proposal of Adachi , and to the currently demonstrated faint-laser pulse system, we demonstrate that a down-conversion source in a Poissonian mode of operation can largely enhance the performance of decoy-state quantum key distribution systems. This makes the down-conversion-based decoy-state system an interesting alternative to current technological implementations based on faint-laser pulses.
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