Visualization of the ‘‘Sisyphus’ ’ attractor

We have performed numerical simulations for a semiconductor diode laser subjected to optical feedback and operating in a chaotic regime. Exploration and investigation of the resulting large data sets call for the application of visualization techniques. Ideally, this should be realized using virtual-reality techniques, but for practical reasons we have opted for a more static approach in the form of a video. Using these techniques we have gained more insight into the dynamical behavior of the laser. Given the rapid development of �graphical � hardware and software, interactive visualization and animation techniques are promising tools to study and understand highly nonlinear problems. © 1997 American Institute of Physics. �S0894-1866�97�01603-9

External cavity modes in Lang-Kobayashi and traveling wave models

We investigate a semiconductor laser with delayed optical feedback due to an external cavity formed by a regular mirror. We discuss similarities and differences of the well-known Lang-Kobayashi delay differential equation model and the traveling wave partial differential equation model. For comparison we locate the continuous wave states in both models and analyze their stability

A fully polynomial approximation scheme for the single machine weighted total tardiness problem with a common due date

We develop a fully polynomial-time approximation scheme (FPTAS) for minimizing the weighted total tardiness on a single machine, provided that all due dates are equal. The FPTAS is obtained by converting an especially designed pseudopolynomial dynamic programming algorithm