Spontaneous symmetry breaking in light emission from heterostructures

Summary form only given. There has been enormous technological and fundamental interest in the ability to shape the direction of optical emission from emitters by suitable control of the surrounding optical modes. Both LEDs and VCSELs use this concept to efficiently project their emission predominantly in the forward direction, while thresholdless lasers and quantum emitters employ similar principles. In all cases, the circular symmetry of the heterostructures is preserved in the optical emission regardless of how energy is injected into them. Using angle-resolved femtosecond and CW spectroscopy, we demonstrate that spontaneous symmetry breaking can indeed occur in which light emerges only on one side of the sample normal.