Focusing properties of semiconductor lasers with broad-area and shaped unstable resonator

Negative branch unstable resonators, with different magnifications, have been fabricated and analyzed. Investigating the focusing properties of our designs, we show that variations in the astigmatism of the beam are dependent on the magnification of the resonator and thermal effects. Given this, we have produced devices with stable astigmatism and good focus points. Numerical simulations were also carried out showing good agreement with experimental results.