Enhancement of Active Medium Pump Efficiency for a Distributed Feedback Waveguide Laser

: pp. 108 - 112
Lviv Polytechnic National University

On the basis of dielectric gratings, in which dielectric permittivity can be complex, and the imaginary part can be both positive and negative, waveguide microlasers are developed. The advantage of waveguide microlasers, comparing to conventional lasers are a low pump threshold, compactness and easy design for optical integration. The structure of distributed feedback (DFB) is considered as the most important configuration of waveguide lasers.

In the article a model of waveguide laser with distributed feedback is calculated using the method of coupled waves. Due to the presence in the waveguide of the active medium and the Bragg grating, with certain grating parameters, laser generation is possible. This is due to the fact that the incident electromagnetic wave on the waveguide layer diffracts on the Bragg grating, while it becomes a waveguide mode. Due to the effect of the resonance of the waveguide mode, there is a laser generation along the normal to the surface of the grating. The necessary condition for laser generation is the optimization of the parameters of the grating and the angle of incidence of the pump beam, which was carried out in this paper.

In this paper we used configuration of the DFB waveguide laser in which Bragg grating was written in active medium. With such theoretical model, we calculated grating parameters, required for laser generation to occur.

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