Laser Action in Pi-Conjugated Polymer Microcavities

Polymers in general are a class of materials known to be excellent insulators. However π-conjugated polymers are different in that they possess semiconductor characteristic properties. They actually can be transformed into excellent conductors with conductivities close to those of good metals by doping. In addition to electrical conductivity, π-conjugated polymers also show luminescence upon electrical or optical excitation. Furthermore stimulated emission is another crucial feature of such materials that provides the possibility of attaining laser action. The present work concentrates on a small class of π-conjugated polymer materials that could provide laser action when optically excited, namely the DOO-PPV polymer. In particular we used the lasing properties of this polymer to investigate a variety of microcavities as well as the natural microcavities that are formed in the polymer films and give rise to random laser action.