Penalty Evaluation Due to the Cascade and Frequency Misalignment of AWG-Based Optical Add-Drop Multiplexers in 10 Gb/s Metro Core Ring Networks

The performance evaluation of AWG-based OADMs due to filter cascade in 10 Gb/s WDM metro core networks is presented. The penalty for the through optical channels is investigated versus the laser wavelength drift and OADM temperature stabilization failure. Results are measured and extrapolated with simulation results to obtain the maximum allowable number of OADMs in the metro network.     

An Experimental ASON Based on OADM Rings and a GMPLS Control Plane

This article presents the architecture of an ASON testbed implemented in the EMPIRICO project, focusing on design and implementation issues of real-time provisioning of bidirectional optical connections supported by a distributed GMPLS-based control plane and triggered by the network management system. Experimental performance is evaluated over a unidirectional and a bidirectional all-optical OADM ring in which neither wavelength converters nor optical resources discovery are employed. Performance analysis evaluates the blocking probability and the connection setup time.     

Cluster modelling of O(1s) core excitons at the (100) surface of alkaline-earth oxides

Calculations have been performed on the O(1s) X-ray absorption spectra of the O^2- ion in the series of alkaline-earth oxides MgO, CaO, SrO. The static exchange approach has been used to calculate the near-edge X-ray absorption fine structure (NEXAFS) spectra for a range of cluster models (up to 50 atoms), representing both the (100) surface and the bulk of the different lattices. The clusters have been embedded in a proper representation of both the surrounding crystal ions and the Madelung potential generated by the infinite crystal. In the surface clusters discrete levels lying around 1.5 eV below the calculated ionization potential were found and characterized. This surface state has been studied further by performing complete active space self-consistent field (CASSCF) calculations in which the polarization of the crystal ions has been taken into account by means of a core polarization potential (CPP) method as well as the Mott-Littleton approach. After inclusion of this potential, the calculated ionization potentials show good agreement with XPS measurements.