Figure 1 (IMAGE) Forschungsverbund Berlin Caption Figure 1. (a) Polariton BEC and phonon lasing of a microstructured trap in a semiconductor microcavity. (b) BEC emission under low (the lower curve) and high (the upper curve) particle densities, displaying phonon sidebands separated by the phonon energy ?ω_a . Credit PDI and Instituto Balseiro and Centro Atómico Usage Restrictions The image may only be used with appropriate caption and credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.