100 Gb/s uncooled WDM system using conventional WDM components and advanced receiver signal processing

We demonstrate an uncooled WDM system using standard WDM components and receiver signal processing, with a different number of receivers to transmitters, to allow wide temperature drift of the transmitter lasers. A 100 Gb/s 8-wavelength demonstrator has been developed, which proves the feasibility of the approach over 25 km of SMF. © 2012 OSA.

Instability of the steady-state regime of generation in laser diodes with a broad gain spectrum

The laser-diode parameters at which the steady-state regime of generation becomes unstable are analyzed within the framework of the mode-locking model. The crucial role of the transverse inhomogeneity of the field, pumping intensity, and spectrum width in developing the instabilities of the steady-state regime of generation is demonstrated. The calculated values of the instability threshold are shown to be consistent with the experimental results. © 2008 Springer Science+Business Media, Inc.

Energy performance certification as a signal of workplace quality

Energy performance labelling and certification have been introduced widely to address market failures affecting the uptake of energy efficient technologies, by providing a signal to support decision making during contracting processes. The UK has recently introduced the Energy Performance Certificate (EPC) as a signal of building energy performance. The aims of this article are: to evaluate how valid EPC's are signals of occupier satisfaction with office facilities; and to understand whether occupant attitudes towards environmental issues have affected commercial office rental values. This was achieved by surveying occupant satisfaction with their workplaces holistically using a novel multi-item rating scale which gathered 204 responses. Responses to this satisfaction scale were matched with the corresponding EPC and rental value of occupier's workplaces. The satisfaction scale was found to be both a reliable and valid measure. The analysis found that EPC asset rating correlates significantly with occupant satisfaction with all facility attributes. Therefore, EPC ratings may be considered valid signals of overall facility satisfaction within the survey sample. Rental value was found to correlate significantly only with facility aesthetics. No evidence suggests rental value has been affected by occupants' perceptions towards the environmental impact of facilities. © 2013 The Authors.

Degenerate mode-group division multiplexing using MIMO digital signal processing

MIMO DSP is employed to improve the performance of degenerate mode-group division multiplexing in 8 km of conventional GI-MMF. Compensation of the mode coupling, induced by the launch and propagation, between and inside each degenerate mode-group is investigated in order to reduce the DSP complexity. © 2013 IEEE.

Transmission of simultaneous 10Gb/s ethernet and radioover-fibre transmission using in-band coding

A technique using spectrum-shaping codes to create nulls in the baseband spectrum of an Ethernet signal, so that several RF signals can be inserted in-band, is demonstrated by simultaneous transmission of 10GbE and WCDMA signals. © 2013 OSA.

Temporal Coherence of Chlorophyll a during a Spring Phytoplankton Bloom in Xiangxi Bay of Three-Gorges Reservoir, China

Algal bloom phenomenon was defined as "the rapid growth of one or more phytoplankton species which leads to a rapid increase in the biomass of phytoplankton", yet most estimates of temporal coherence are based on yearly or monthly sampling frequencies and little is known of how synchrony varies among phytoplankton or of the causes of temporal coherence during spring algal bloom. In this study, data of chlorophyll a and related environmental parameters were weekly gathered at 15 sampling sites in Xiangxi Bay of Three-Gorges Reservoir (TGR, China) to evaluate patterns of temporal coherence for phytoplankton during spring bloom and test if spatial heterogeneity of nutrient and inorganic suspended particles within a single ecosystem influences synchrony of spring phytoplankton dynamics. There is a clear spatial and temporal variation in chlorophyll a across Xiangxi Bay. The degree of temporal coherence for chlorophyll a between pairs of sites located in Xiangxi Bay ranged from -0.367 to 0.952 with mean and median values of 0.349 and 0.321, respectively. Low levels of temporal coherence were often detected among the three stretches of the bay (Down reach, middle reach and upper reach), while high levels of temporal coherence were often found within the same reach of the bay. The relative difference of DIN between pair sites was the strong predictor of temporal coherence for chlorophyll a in down and middle reach of the bay, while the relative difference in Anorganic Suspended Solids was the important factor regulating temporal coherence in middle and upper reach. Contrary to many studies, these results illustrate that, in a small geographic area (a single reservoir bay of approximately 25 km), spatial heterogeneity influence synchrony of phytoplankton dynamics during spring bloom and local processes may override the effects of regional processes or dispersal.

Integration of silicon plasmonic schottky photodetector for on chip signal tapping at telecom wavelengths

We experimentally demonstrate the use of an on-chip integrated Schottky plasmonic detector for testing, monitoring and tapping signals in plasmonic and photonic devices. Theoretical model and measurement of external and integrated devices will be presented. © OSA 2013.

Integration of silicon plasmonic schottky photodetector for on chip signal tapping at telecom wavelengths

We experimentally demonstrate the use of an on-chip integrated Schottky plasmonic detector for testing, monitoring and tapping signals in plasmonic and photonic devices. Theoretical model and measurement of external and integrated devices will be presented. © OSA 2013.

Integration of silicon plasmonic schottky photodetector for on chip signal tapping at telecom wavelengths

We experimentally demonstrate the use of an on-chip integrated Schottky plasmonic detector for testing, monitoring and tapping signals in plasmonic and photonic devices. Theoretical model and measurement of external and integrated devices will be presented. © OSA 2013.

100 Gb/s uncooled WDM system using conventional WDM components and advanced receiver signal processing

We demonstrate an uncooled WDM system using standard WDM components and receiver signal processing, with a different number of receivers to transmitters, to allow wide temperature drift of the transmitter lasers. A 100 Gb/s 8-wavelength demonstrator has been developed, which proves the feasibility of the approach over 25 km of SMF. © 2012 Optical Society of America.

18 Gchips/s electronically-processed OCDMA spread spectrum for access networks

We demonstrate for the first time coding/decoding for OCDMA networks using electronic transversal filters at 18Gchips/s-a ten-fold improvement over previous demonstrations. The chip rate allows users at Gb/s rates in access applications. © 2007 Optical Society of America.

A novel SOA-based crosspoint switch for mixed signal distribution

A 3x3 SOA-based switch is demonstrated for routing both radio-over-fiber and digital signals simultaneously. High extinction ratio digital baseband signals are transmitted and sufficient linearity is found for high performance RF signal distribution. © 2006 Optical Society of America.

Doping dependence of the Raman spectrum of defected graphene.

We investigate the evolution of the Raman spectrum of defected graphene as a function of doping. Polymer electrolyte gating allows us to move the Fermi level up to 0.7 eV, as directly monitored by in situ Hall-effect measurements. For a given number of defects, we find that the intensities of the D and D' peaks decrease with increasing doping. We assign this to an increased total scattering rate of the photoexcited electrons and holes, due to the doping-dependent strength of electron-electron scattering. We present a general relation between D peak intensity and defects valid for any doping level.