Experimental investigation of inter-modal cross-gain modulation and transient effects in a two mode group erbium doped fiber amplifier

We report what we believe to be the first experimental study of inter-modal cross-gain modulation and associated transient effects as different spatial modes and wavelength channels are added and dropped within a two-mode amplifier for SDM transmission

Epistemic policy networks in the European Union’s CBRN risk mitigation policy

This paper offers insights into an innovative and currently flagship approach of the European Union (EU) to the mitigation of chemical, biological, radiological, and nuclear (CBRN) risks. Building on its long-time experience in the CBRN field, the EU has incorporated methods familiar to the students of international security governance: it is establishing regional networks of experts and expertise. CBRN Centers of Excellence, as they are officially called, aim to contribute to the security and safety culture in different parts of Africa, the Middle East, South East Asia, and South East Europe, in the broadly construed CBRN area. These regional networks represent a modern form of security cooperation, which can be conceptualized as an epistemic policy networks approach. It offers flexibility to the participating states, which have different incentives to get involved. At the same, however, the paper identifies potential limitations and challenges of epistemic policy networks in this form

Multimode EDFA performance in mode-division multiplexed transmission systems

We report a detailed study on the system performance of a two-mode group EDFA. In particular we quantify how the gain spectrum and BER performance are affected by input signal and pump power as required in the execution of our ongoing MDM transmission experiments

Electromagnetic processes in strong crystalline fields

As an addendum to the NA63 proposal cite{Ande05}, we propose to measure 1) the Landau-Pomeranchuk-Migdal (LPM) effect in low-$Z$ targets, 2) Magnetic suppression of incoherent bremsstrahlung resulting from exposure to an external field during the emission event, and 3) the bremsstrahlung emission from relativistic ($gamma=170$), fully stripped Pb nuclei penetrating various amorphous targets. Concerning the LPM effect, both the 'traditional' Migdal approach and the modern treatment by Baier and Katkov display inaccuracies, i.e. a possible lack of applicability in low-$Z$ targets. Moreover, the LPM effect has been shown to have a significant impact on giant air showers for energies in the EeV range - evidently processes in a low-$Z$ material. A measurement of magnetic suppression is demanding in terms of necessary accuracy (an expected $lesssim$15% effect), but would prove the existence of a basic interplay between coherent and incoherent processes, also believed to be significant in beamstrahlung emission. For bremsstrahlung from Pb$^{82+}$: In contrast to earlier expectations, recent investigations have shown that the bremsstrahlung emission from heavy, relativistic particles does not appear with constant power for all photon energies up to the end-point given by the energy of the incident ion, but instead the spectrum has a peaked shape, due to the finite size of the nucleus. Beyond an energy of about $2gammahbaromega_1$, wher e $hbaromega_1$ corresponds to the energy transfer above which the $Z$ protons in the nucleus can be considered quasi-free, the power-spectrum falls off quite steeply, eventually leaving pair production as the dominant energy loss mechanism for sufficiently high values of the Lorentz-factor

High capacity multi-mode transmission systems using higher-order modulation formats

We look at multi-mode fiber as potential means to upgrade capacity of optical transmission systems compared to current single-mode technology by employing multiple modes as transmission lanes as well as using higher-order modulation formats

Experimental Test of a Newly Proposed Empirical Relationship between the Centroid and Width of the Giant Quadrupole-Resonance and the Neutron Binding-Energy of the Nucleus

Journals published by the American Physical Society can be found at http://publish.aps.org

Mode-division-multiplexed 3x112-Gb/s DP-QPSK transmission over 80-km few-mode fiber with inline MM-EDFA and blind DSP

We show transmission of a 3x112-Gb/s DP-QPSK mode-multiplexed signal up to 80km, without and with multi-mode EDFA, using blind 6x6 MIMO digital signal processing. We show that the OSNR-penalty induced by mode-mixing in the multi-mode EDFA is negligible

Crossing the Dripline to 11N Using Elastic Resonance Scattering

The level structure of the unbound nucleus 11N has been studied by 10C+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a 10C beam with an energy of 9.0 MeV/u. An additional measurement was done at the A1200 spectrometer at MSU. The excitation function above the 10C+p threshold has been determined up to 5 MeV. A potential-model analysis revealed three resonance states at energies 1.27 (+0.18-0.05) MeV (Gamma=1.44 +-0.2 MeV), 2.01(+0.15-0.05) MeV, (Gamma=0.84 +-$0.2 MeV) and 3.75(+-0.05) MeV, (Gamma=0.60 +-0.05 MeV) with the spin-parity assignments I(pi) =1/2+, 1/2- and 5/2+, respectively. Hence, 11N is shown to have a ground state parity inversion completely analogous to its mirror partner, 11Be. A narrow resonance in the excitation function at 4.33 (+-0.05) MeV was also observed and assigned spin-parity 3/2-.Comment: 14 pages, 9 figures, twocolumn Accepted for publication in PR