Mindaugas Radziunas

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We investigate the longitudinal dynamics of multisection semiconductor lasers based on a model, where a hyperbolic system of partial differential equations is nonlinearly coupled with a system of ordinary differential equations. We present analytic results for that system: global existence and uniqueness of the initial-boundary value problem, and existence(More)
An in-depth theoretical as well as experimental analysis of the nonlinear dynamics in semiconductor lasers with active optical feedback is presented. Use of a monolithically integrated multisection device of submillimeter total length provides access to the short-cavity regime. By introducing an amplifier section as a special feature, phase and strength of(More)
Semiconductor lasers are efficient light sources with an important drawback, the lack of an intrinsic mode selection mechanism which leads to spatio-temporal instabilities. The modulation instability that unstabilizes the homogeneous solution can be suppressed by the introduction of spatial modulations in the transverse and longitudinal directions. The(More)
The spatial modulation of pump in broad emission area semiconductor amplifiers has two important advantages in this kind of devices. A 2-dimensional periodic modulation of the pump profile introduces by one side, a filtering effect and an improvement of the beam quality. Moreover, the spatial modulation changes the effective diffraction inside the material(More)
We report the results of numerical and experimental investigations of the dynamics in an external cavity diode laser device composed of a semiconductor laser and a distant Bragg grating, which provides an optical feedback. The traveling wave model was used to simulate and analyze the nonlinear dynamics of the considered laser device. Finally, it is shown,(More)
In the present paper a general technique is developed for construction of compact high-order finite difference schemes to approximate Schrödinger problems on nonuniform meshes. Conservation of the finite difference schemes is investigated. The same technique is applied to construct compact high-order approximations of the Robin and Szeftel type boundary(More)