SUPERRADIANT FILM LASER OPERATION IN RED PERYLIMIDE DYE-DOPED SILICA POLYMETHYLMETHACRYLATE COMPOSITE

A new composite silica-polymethylmethacrylate glass material has been synthesized and doped by red perylimide dye ROT 300. Film coatings on ordinary glass plates were prepared. With second harmonic Nd:YAG laser pumping, such a structure exhibits laser properties when the emitted light is trapped and propagates in the supporting glass plate, producing a lasing effect at 623 nm with almost-equal-to 0.1 mJ threshold and about 9 nm spectral bandwidth (but 70 nm for spontaneous emission). A significant amplification could be attributed to multiple inward total reflections of emitted light within the excited zone near to critical support-film boundary angles, while the emission from excited molecules within the film is stimulated by either evanescent wave propagation along the boundary, or by resonant energy coupling of waves propagating inside the support waveguide to leaky modes propagating inside the active film.