Temperature-induced unstable-resonator semiconductor lasers

In summary, we have demonstrated that monolithically integrated heater unstable resonator semiconductor lasers can be used to control the transverse modes and to generate good quality output beams. This laser is easy to make and does not suffer from scattering loss as might happen at the interfaces in regrown lens designs, or due to the surface roughness in the case of etched curved mirrors. This effective negative unstable resonator can be tuned by controlling the heating current, and can be useful in studying unstable resonator lasers. Beam steering is observed and it is found that beam position can be moved by controlling temperature gradients across the laser