Lasing in organic mixed-crystal thin films with cavities composed of naturally formed cracks.

This study investigates the possibility that a crack pair that is naturally formed in the course of sample preparation functions as a laser cavity. Lasing with longitudinal mode structures has been reported in mixed-crystal thin films composed of fluorene and anthracene without artificial cavity structure. In the present study, it was shown that lasing is observed only when an excitation spot covers parallel pairs of cracks.

Room-temperature lasing from fluorene thin-film crystals densely doped with anthracene.

The potential for room-temperature lasing in densely doped organic crystals has been examined using (fluorene)0.8-(anthracene)0.2 thin crystals fabricated in a narrow gap between two quartz plates.