Abstract
In this study, the authors present an innovative gain clamping method to mitigate Erbium-doped fibre amplifiers transients under bursty or packetised traffic. This method is based on a lasing technique by means of a continuous wave feedback signal reflected on a fibre Bragg grating. The clamping was assessed using on a range of re-injected powers from -30 to -5 dBm and able to fully mitigate the packet transients. The performance of the system at 2.5 and 10.0 Gb/s was appraised for different inter-packets times being observed in all cases an improvement in the Q factor. Additionally, a study that includes a characterisation of the transients (gain excursion and decaying time) with the inter-packet parameters and a comparison with theory was also presented.

Abstract
For the characterization of TV White Spaces (TVWS), an extensive simulation of the impact of interfering signals was undertaken in a generalized scenario. The simulation for these investigations was derived from a Monte Carlo methodology using SEAMCAT, and the results include the computation of TVWS maps as it can be done with the access to a geo-location database, or based on autonomous sensing only. Geo-location database approach is shown to utilize TVWS spectrum more efficiently. The impact of Professional Wireless Microphone Systems (PWMS) devices on the availability of TVWS is also analyzed and imposes additional limitations of the maximum power emitted by secondary spectrum users. © 2011 IIMC.

Abstract
The characteristics of MZI-SOA are affected by its internal design yields and asymmetries, leading to an unbalanced power distribution at the output arms and difficult or non optimum biasing. Therefore, we propose an experimental methodology and model for MZI-SOA structures taking into account internal asymmetries as well as the internal SOA behaviour under different current both as what regards amplitude and phase.

Abstract
In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An improvement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 dB.

Abstract
We demonstrate, by using multiple Mach-Zehnder interferometer (MZI)-semiconductor optical amplifier structures, an all-optical synchronous D type flip-flop, with high-photonic integration capability. Experimental performance analysis shows its functional and performance feasibility and high-switching speeds were achieved. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1201-1204, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25998

Abstract
This work focuses on the evaluation of different sensing techniques for the detection of wireless microphones in the UHF band, by means of simulation. The metrics used for the comparisons include probability of detection, probability of false alarm and minimum SNR detected for a given observation time. The energy detector is used as a benchmark against blind detection techniques. As an example, simulation results showed that blind detection algorithms can sense a wireless microphone signal with SNR = -17 dB in a Rayleigh channel, considering 100 ms sensing time, 90 % probability of detection and 10 % probability of false alarm.