Design optimization of a hyperbolic unstable-resonator semiconductor laser

A semiconductor laser with a hyperbolic unstable resonator has been investi gated through numerical simulations. The laser has an integrated focusing g rating outcoupler. The complete device, including the resonator, outcoupler , and free-space propagation, has been modeled. Propagation in the resonato r and the outcoupler grating has been modeled using a beam-propagation meth od that accounts for anti-guiding and thermal effects. The work has been ai med at optimizing the resonator layout for suppressed filamentation and wav efront distortion, i.e., to design a laser that produces an injection-indep endent focused spot. We show that small changes in the resonator layout can have a large effect on the laser performance and characteristics of the fo cused spot. We conclude that thermal effects, rather than anti-guiding effe cts, limit the performance of the device.