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Directional reversals and multimode dynamics in semiconductor ring lasers
2013, Pérez-Serrano, Antonio, Javaloyes, Julien, Balle, Salvador
We investigate the dynamics of longitudinal modes in quantum-well semiconductor ring lasers by means of a spatio-temporal travelling wave model. We report the existence of a novel multimode instability in such a system that provokes a periodic deterministic directional reversal involving jumps between consecutive longitudinal modes. The switching sequence follows the modal frequencies from blue to red, and every modal jump is accompanied by a reversal of the direction of emission. We characterize and analyze such instability via the bifurcation analysis of the full travelling wave model as well as by performing the linear stability analysis of the monochromatic solutions.
Spectral delay algebraic equation approach to broad area laser diodes
2012, Pérez-Serrano, Antonio, Javaloyes, Julien, Balle, Salvador
In this work, we discuss an efficient modeling approach for the simulation of Broad Area Laser Diodes. Our method is based on the analytical solution in the spectral domain of the paraxial wave equations for the forward and backward slowly varying traveling waves. We show how to extend to the lateral dimension and to the influence of diffractive terms the idea of mesh decimation by recasting traveling wave models into coupled delay algebraic equations, as discussed in [1]. We compare the results of the dynamics obtained with our improved model with the results of a standard traveling wave description in the cases of straight current stripes as well as in the important configuration of high power tapered anti-reflection coated devices. We obtain an excellent agreement and an improvement of the integration time between one and two orders of magnitudes which may alleviate the necessity of using complex parallel codes. We discussed how the method can be further improved to other, more refined descriptions of the active medium and to the inclusion of thermal effects.
Multi-channel wavelength conversion using four-wave mixing in semiconductor ring lasers
2012, Pérez-Serrano, Antonio, Javaloyes, Julien, Balle, Salvador
We theoretically study all-optical simultaneous wavelength conversion of multiple channels by four-wave mixing in semiconductor ring lasers. Locking the semiconductor ring laser to a holding beam allows to achieve large conversion efficiencies with good signal-tonoise ratio in several channels at multi-Gb/s bit rates. Cross-talk between signals, arising from the peculiar four-wave mixing cascade of modes in semiconductor ring lasers and their cross-gain saturation, is studied in detail. We show that it can be controlled by adjusting the intensity of the holding beam, the bias current of the laser and the number, intensity and wavelength of signals that one wants to convert.