Design optimization of a hyperbolic unstable-resonator semiconductor laser

A semiconductor laser with a hyperbolic unstable resonator has been investigated through numerical simulations. The laser has an integrated focusing grating outcoupler. The complete device, including the resonator, outcoupler, and free-space propagation, has been modeled. Propagation in the resonator and the outcoupler grating has been modeled using a beam-propagation method that accounts for anti-guiding and thermal effects. The work has been aimed at optimizing the resonator layout for suppressed filamentation and wavefront distortion, i.e., to design a laser that produces an injection-independent focused spot. We show that small changes in the resonator layout can have a large effect on the laser performance and characteristics of the focused spot. We conclude that thermal effects, rather than anti-guiding effects, limit the performance of the device