Abstract

The optical power that can be extracted from a semiconductor laser is limited due to catastrophic optical damage and one path to circumvent this limit is to increase the volume of the lasing mode. In the simplest case, this is achieved by increasing the lateral dimension. However, the emission profile of Broad-Area Laser Diodes (BALDs) usually presents a low quality and it is prone to instabilities. The large BALDs lateral dimension allows for many lateral modes that are nearly degenerated in gain which leads to multi-peaked near-fields and carrier-induced self-focusing might even lead to chaotic filamentation. Such a complex problem calls for an accurate and fast modeling approach. From the numerical point of view, the two-dimensional character of the field and of the carrier distributions combined with the large spectral width of the semiconductor gain curve result in models that are characterized by a huge number of degrees of freedom (DOF). Such large numbers of DOF demand an exceedingly large computing power for performing exhaustive simulations in the asymptotic regimes using standard Finite-Differences Time-Domain (FDTD) approaches. In addition, all the spatially resolved and time dependent approaches are hindered by the stiffness of laser dynamics: to properly account for the broad gain spectrum one must use an appropriately small time step δt, while the CFL numerical stability condition imposes an accordingly fine spatial step δz.

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