Performance comparison of multi-wavelength conversion using SOA-MZI and DSF for optical wavelength multicast

The electronic layer multicast is going to face the speed and capacity bottleneck of the future optical data networks. Transparent optical wavelength multicast by multi-wavelength conversion is an effective way of achieving data multicast in the optical domain without any optical-electronic-optical conversion. In this paper, two multiple wavelength conversion technologies for 10 Gb/s data rate are investigating and discussed. The first technology is based on cross-phase modulation in a semiconductor optical amplifier – Mach-Zehnder interferometer, and the second is based on four-wave mixing in a dispersion-shifted fiber. We present the simulated performance comparison of two approaches obtained using VPItransmissionMakerTMWDM simulator. Afterwards, we analyze these results in comparison with our previous experimental results of the same schemes

Multifunctional photonic integrated circuit for diverse microwave signal generation, transmission and processing

Microwave photonics (MWP) studies the interaction between microwave and optical waves for the generation, transmission and processing of microwave signals (i.e., three key domains), taking advantages of broad bandwidth and low loss offered by modern photonics. Integrated MWP using photonic integrated circuits (PICs) can reach a compact, reliable and green implementation. Most PICs, however, are recently developed to perform one or more functions restricted inside a single domain. In this paper, as highly desired, a multifunctional PIC is proposed to cover the three key domains. The PIC is fabricated on InP platform by monolithically integrating four laser diodes and two modulators. Using the multifunctional PIC, seven fundamental functions across microwave signal generation, transmission and processing are demonstrated experimentally. Outdoor field trials for electromagnetic environment surveillance along an in-service high-speed railway are also performed. The success to such a PIC marks a key step forward for practical and massive MWP implementations.Comment: 17 page

Performance evaluation of an optical transparent access tier based on PON and spectral codes

The increasing amount of bandwidth requirements and quality of service needs for the next-generation access networks has boosted extensive research in the fiber-optics communication field. In this light, passive optical networks (PONs) combined with optical code division multiple access (OCDMA), provide a potentially cost-effective solution to meet such bandwidth demands. This work proposes an optical transparent architecture which enables all-optical communication between the network nodes. The encoded data streams are multiplexed at a merging point which results in multiple user interference (MUI), thus significantly reducing the network throughput. The networking nodes are able to monitor and record user activity in the PON, and further register the (past) state of activity at the merging point. In this work, we study the coherence of state between the networking nodes and the merging point, for different packet size distributions, in order to predict an optimal transmission instant of each node's data packets. We note that the states are coherent depending on the packet size distribution

Electron-beam propagation in a two-dimensional electron gas

A quantum mechanical model based on a Green's function approach has been used to calculate the transmission probability of electrons traversing a two-dimensional electron gas injected and detected via mode-selective quantum point contacts. Two-dimensional scattering potentials, back-scattering, and temperature effects were included in order to compare the calculated results with experimentally observed interference patterns. The results yield detailed information about the distribution, size, and the energetic height of the scattering potentials.Comment: 7 pages, 6 figure

Obesity-induced chronic inflammation in C57Bl6J mice, a novel risk factor in the progression of renal AA amyloidosis?

Background: Compelling evidence links obesity induced systemic inflammation to the development of chronic kidney disease (CKD). This systemic inflammation may result from exacerbated adipose inflammation. Besides the known detrimental effects of typical pro-inflammatory factors secreted by the adipose tissue (TNF-α, MCP-1 and IL-6) on the kidney, we hypothesize the enhanced obesity-induced secretion of serum amyloid A (SAA), an acute inflammatory protein, to play a key role in aggravating obesity-induced CKD. Methods: Groups of male C57Bl/6J mice (n = 99 in total) were fed a low (10% lard) or high (45% lard) fat diet for a maximum of 52 weeks. Mice were sacrificed after 24, 40 and 52 weeks. Whole blood samples, kidneys and adipose tissues were collected. The development of adipose and renal tissue inflammation was assessed on gene expression and protein level. Adipocytokine levels were measured in plasma samples. Results: A distinct inflammatory phenotype was observed in the adipose tissue of HFD mice prior to renal inflammation, which was associated with an early systemic elevation of TNF-α, leptin and SAA (1A-C). With aging, sclerotic lesions appeared in the kidney, the extent of which was severely aggravated by HFD feeding. Lesions exhibited typical amyloid characteristics (2A) and pathological severity positively correlated with bodyweight (2B). Interestingly, more SAA protein was detected in lesions of HFD mice. Conclusion: Our data suggest a causal link between obesity induced chronic inflammation and AA amyloidosis in C57Bl/6J mice. Though future studies are necessary to prove this causal link and to determine its relevance for the human situation, obesity may hence be considered a risk factor for the development and progression of renal AA amyloidosis in the course of CKD. (Figure Presented)

Probing the potential landscape inside a two-dimensional electron-gas

We report direct observations of the scattering potentials in a two-dimensional electron-gas using electron-beam diffaction-experiments. The diffracting objects are local density-fluctuations caused by the spatial and charge-state distribution of the donors in the GaAs-(Al,Ga)As heterostructures. The scatterers can be manipulated externally by sample illumination, or by cooling the sample down under depleted conditions.Comment: 4 pages, 4 figure

Simulation and experimental characterization of SOA-MZI-based multiwavelength conversion

We present, for the first time, extensive simulation and experimental characterizations of single SOA-MZI-based multiwavelength conversion (MWC) of NRZ data at 10 Gb/s and RZ data at 40 Gb/s under various parametric conditions deploying ITU standard 100- and 200-GHz channel spacing. We analyze, in particular, the physical performance impairments caused by high-order four-wave mixing interference. Our simulation results indicate the promising performance of the MWC up to eight channels with 200-GHz channel spacing. We further experimentally demonstrate four-channel 10-Gb/s error-free MWC with signal regeneration possibilities and 40-Gb/s MWC with moderate penalties, based on commercially available integrated SOA-MZIs. We obtained clear, open converted eye diagrams and achieved negligible difference in channel performance among all MWC channels at both bit rates. Our results proved the excellent performance of a simple scheme for various future network and system applications, such as all-optical wavelength multicast and grid networking

Phase modulation parallel optical delay detector for microwave angle-of-arrival measurement with accuracy monitored

A novel phase modulation parallel optical delay detector is proposed for microwave angle-of-arrival (AOA) measurement with accuracy monitored by using only one dual-electrode Mach-Zenhder modulator. A theoretical model is built up to analyze the proposed system including measurement accuracy monitoring. The spatial delay measurement is translated into the phase shift between two replicas of a microwave signal. Thanks to the accuracy monitoring, the phase shifts from 5{\deg} to 165{\deg} are measured with less than 3.1{\deg} measurement error