The lasing threshold for crystalline anthracene sandwiched within an optical microcavity consisting of two dielectric Bragg reflectors (DBRs) is found to decrease by an order of magnitude as temperature is reduced from 300 to 12 K while maintaining an energy dispersion characteristic of the cavity polariton across the entire temperature range studied. The linear temperature dependence differs from a conventional organic semiconductor laser that shows practically no variation in threshold over the same temperature range. The two-dimensional Bose-Einstein condensate (BEC) critical density and its relation to the polariton lasing threshold is considered in the thermodynamic limit along with other temperature-dependent processes that are used to explain our observations.

• Received 14 April 2012

DOI:https://doi.org/10.1103/PhysRevB.86.045312