Waveguide and Γ-factor optimization for low-divergence ridge lasers

The work is aimed for analytical approach to maximize ridge laser modal gain at a given beam divergence in a vertical direction. When the gain/loss profile of planar waveguide is known the equation for optimum near-field profile was obtained. Surprisingly, it is appeared to be Schrödinger type equation where normalized gain/loss profile plays role of potential energy. The developed approach was applied to a few examples widely met in practice. Also it was checked whether usage of leaky waveguides is justified or not. (paper)