We report on a technique that serves to eliminate pointing instability in Quantum Cascade
lasers by suppressing the propagation of higher order transverse modes within the laser
cavity. This process, achieved via a short and lossy lateral constriction in the waveguide,
only allows the fundamental mode to propagate. The beam pointing fluctuations of the
modified devices are greatly reduced, with a 10-fold improvement in standard deviation,
indicating a stable emitted beam. The far-field pattern has a Gaussian shape, and the slope …