Lasing from all-polymer microcavities

We report on the laser action in a microcavity where both the dielectric mirrors and the active material have a macromolecular nature, resulting in a full plastic laser device. Distributed Bragg reflectors (DBRs) are prepared by spin-coating of polyvinylcarbazole and cellulose acetate orthogonal solutions and the active layer consists of a highly fluorescent conjugated polymer poly(9,9-dioctylfluorenyl-2,7-diyl-co-1,4-benzo-(2,1 ' -3)-thiadiazole) (F8BT) spun film. A quality factor in the range 80–180 is achieved and the cavity mode is carefully tuned on the peak of the F8BT amplified spontaneous emission spectrum. Under pulsed optical pumping, laser emission is obtained with a surprisingly low lasing threshold (<20 μJ cm −2 ) for a full plastic DBR optical cavity. This result opens a simple and cheap way to obtain a new class of polymer lasers.