Optical injection locking of semiconductor lasers has attracted significant attention due to its applications in laser analysis, modulation characteristic enhancement, and nonlinear dynamics. In many cases, the analysis of the optically injected laser is done by simulation, requiring an accurate laser model and, therefore, an adequate modeling of the gain compression at high photon densities. We use the Kobayashi-Lang rate equations to numerically compare the stable locking range considering four different gain models. Results reveal that at low bias currents, gain compression is significant only under weak injection regime. In contrast, for higher bias current, gain compression must be considered both in weak and strong injection regimes.
We present results on the usefulness of multilevel networks from the viewpoint of Radio over Fiber networks. We show results of several topology options as star, ring, multi-level ring, multi-level star, hybrid multi-level ring/star and hybrid multi-level star/ring. We present comparative results of the topologies in terms of fiber distance, and reliability of the networks.
One of the most immediate benefits of MPLS is the ability to perform traffic engineering. Traditionally, the only mechanism for redirecting traffic has been to change the link metrics in the Interior Gateway Protocol (IGP, responsible for routing within a site), but this can potentially change the paths of all the packets traversing that link. With MPLS there is a finer granularity because it does not operate on a link basis and therefore it is possible to shift individual LSPs from congested paths to an alternate path. This also simplifies the operation of the network operator since the network operator can assign global optimization algorithms that provide mapping from the traffic demand to the physical link that could not be done using local optimization. Constraint-based routing (or its variant Explicit Routing ER) allows for traffic engineering. What is important, however, is that ER can allow for distributed routing of the same type as the routing and wavelength assignment in the optical adaptation layer. Furthermore, constraint-based routing use topology/resources updates to perform distributed LSP route computations, which can be used to deploy distributed shortest-path lightpath routing. A detailed comparison between distributed path routing strategies based on traffic parameters and fix path routing schemes is presented in this paper and it is shown that a distributed path routing scheme based on traffic correlation parameter is superior than fix path routing schemes.
Required limits of transmission distance, nodes cascadability and grade of transparency (number of regenerators) are presented to implement semi-transparent DWDM backbone networks. Results are based on OSNR performance of three realistic optical network scenarios. Optical transmission impairments are key issues for transparent optical networks. To improve transmission in an optical network one can use forward error correction (FEC), Raman amplification, robust modulation formats tolerant to non-linear effects and noise, optimised dispersion maps, semi-transparent OXC architectures with selective 3R or 2R regeneration and reduction of losses in the optical cross connector (OXCs) architectures. In a typical optical network with mesh topology, a transmitted optical signal is expected to traverse several nodes connecting any source-destination pair. The cascadability limit of transparent optical cross-connect (OXC) nodes and the transmission distance between OXC nodes are crucial network design parameters. The required limits of transmission distance, OXC nodes cascadability and number of regenerators per node are presented for DWDM backbone networks. OXC architectures with low loss components and cost effective distributive amplification is required to facilitate a high OSNR and reduce the regeneration rate of semi-transparent networks. OXC architectures with OSNR below 36.7 dB are capable of reducing the regeneration rate to 13% for realistic network topologies.