Wireless internet architecture and testbed for wineglass

One of the most challenging issues in the area of mobile communication is the deployment of IPbased wireless multimedia networks in public and business environments. The public branch may involve public mobile networks, like UMTS as 3G system, while the business branch introduces local radio access networks by means of W-LANs. Conventional mobile networks realise mobile specific functionality, e.g. mobility management or authentication and accounting, by implementing appropriate mechanisms in specific switching nodes (e.g. SGSN in GPRS). In order to exploit the full potential of IP networking solutions a replacement of these mechanisms by IP-based solutions might be appropriate. In addition current and innovative future services in mobile environments require at least soft-guaranteed, differentiated QoS. Therefore the WINE GLASS project investigates and implements enhanced IP-based techniques supporting mobility and QoS in a wireless Internet architecture. As a means to verify the applicability of the implemented solutions, location-aware services deploying both IP-mobility and QoS mechanisms will be implemented and demonstratedPeer ReviewedPostprint (published version

T160‐phosphorylated CDK2 defines threshold for HGF‐dependent proliferation in primary hepatocytes

Liver regeneration is a tightly controlled process mainly achieved by proliferation of usually quiescent hepatocytes. The specific molecular mechanisms ensuring cell division only in response to proliferative signals such as hepatocyte growth factor (HGF) are not fully understood. Here, we combined quantitative time-resolved analysis of primary mouse hepatocyte proliferation at the single cell and at the population level with mathematical modeling. We showed that numerous G1/S transition components are activated upon hepatocyte isolation whereas DNA replication only occurs upon additional HGF stimulation. In response to HGF, Cyclin:CDK complex formation was increased, p21 rather than p27 was regulated, and Rb expression was enhanced. Quantification of protein levels at the restriction point showed an excess of CDK2 over CDK4 and limiting amounts of the transcription factor E2F-1. Analysis with our mathematical model revealed that T160 phosphorylation of CDK2 correlated best with growth factor-dependent proliferation, which we validated experimentally on both the population and the single cell level. In conclusion, we identified CDK2 phosphorylation as a gate-keeping mechanism to maintain hepatocyte quiescence in the absence of HGF

Исследование датчиков рН и удельной электрической проводимости фирмы WTW в системе автоматизированного контроля качества очистки сточных вод

We demonstrate the suitability of microcavities based on circular grating resonators (CGRs) as fast switches. This type of optical resonator is characterized by a high quality factor and very small mode volume. The waveguide-coupled CGRs are fabricated with silicon-on-insulator technology compatible with standard complementary metal-oxide semiconductor (CMOS) processing. The linear optical properties of the CGRs are investigated by transmission spectroscopy. From 3D finite-difference time-domain simulations of isolated CGRs, we identify the measured resonances. We probe the spatial distribution and the parasitic losses of a resonant optical mode with scanning near-field optical microscopy. We observe fast all-optical switching within a few picoseconds by optically generating free charge carriers within the cavity. (C) 2009 Optical Society of Americ

Silicon-organic hybrid electro-optical devices

Organic materials combined with strongly guiding silicon waveguides open the route to highly efficient electro-optical devices. Modulators based on the so-called silicon-organic hybrid (SOH) platform have only recently shown frequency responses up to 100 GHz, high-speed operation beyond 112 Gbit/s with fJ/bit power consumption. In this paper, we review the SOH platform and discuss important devices such as Mach-Zehnder and IQ-modulators based on the linear electro-optic effect. We further show liquid-crystal phase-shifters with a voltage-length product as low as V pi L = 0.06 V.mm and sub-mu W power consumption as required for slow optical switching or tuning optical filters and devices

Low-power silicon-organic hybrid (SOH) modulators for advanced modulation formats

We demonstrate silicon-organic hybrid (SOH) electro-optic modulators that enable quadrature phase-shift keying (QPSK) and 16-state quadrature amplitude modulation (16QAM) with high signal quality and record-low energy consumption. SOH integration combines highly efficient electro-optic organic materials with conventional silicon-on-insulator (SOI) slot waveguides, and allows to overcome the intrinsic limitations of silicon as an optical integration platform. We demonstrate QPSK and 16QAM signaling at symbol rates of 28 GBd with peak-to-peak drive voltages of 0.6 Vpp. For the 16QAM experiment at 112 Gbit/s, we measure a bit error ratio of 5.1 × 10-5 and a record-low energy consumption of only 19 fJ/bit

High-speed, low-power optical modulators in silicon

Silicon modulators are maturing and it is anticipated that they are going to substitute state-of-the art modulators. We review current silicon modulator approaches and then discuss the silicon-organic hybrid (SOH) approach in more detail. The SOH approach has recently enabled the operation with an energy consumption of 60 fJ/bit and demonstrated the generation of up to 112 Gbit/s per polarization in a compact silicon modulator of 1.5 mm length

Ultrafast all-optical switching in a silicon-nanocrystal-based silicon slot waveguide at telecom wavelengths

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technica editing by the publisher. To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.htmlWe demonstrate experimentally all-optical switching on a silicon chip at telecom wavelengths. The switching device comprises a compact ring resonator formed by horizontal silicon slot waveguides filled with highly nonlinear silicon nanocrystals in silica. When pumping at power levels about 100 mW using 10 ps pulses, more than 50% modulation depth is observed at the switch output. The switch performs about I order of magnitude faster than previous approaches on silicon and is fully fabricated using complementary metal oxide semiconductor technologies.The work was financially supported by the EU through project PHOLOGIC (FP6-IST-NMP-017158).Martínez Abietar, AJ.; Blasco Solbes, J.; Sanchis Kilders, P.; Galan Conejos, JV.; García-Rupérez, J.; Jordana, E.; Gautier, P.... (2010). Ultrafast all-optical switching in a silicon-nanocrystal-based silicon slot waveguide at telecom wavelengths. Nano Letters. 10(4):1506-1511. doi:10.1021/nl9041017S1506151110

Silicon-Organic Hybrid MZI Modulator Generating OOK, BPSK and 8-ASK Signals for up to 84 Gbit/s

We report on high-speed multilevel signal generation and arbitrary pulse shaping with silicon-organic hybrid (SOH) Mach-Zehnder interferometer (MZI) modulators. Pure phase modulation exploiting the linear electrooptic effect allows the generation of multiple modulations formats at highest speed such as 40-Gbit/s on-off-keying (OOK) and binary-phase-shift keying (BPSK) and 28-Gbd 4-ASK and 8-ASK with data rates up to 84 Gbit/s. Additionally, beside NRZ pulse shaping, for the first time, Nyquist pulse shaping with silicon modulators is demonstrated to enable multiplexing at highest spectral efficiency