Tunable distributed feedback lasing with a threshold in the nanojoule range in an organic guest-host polymeric waveguide

Tunable distributed feedback lasing was achieved in a guest-host polymeric waveguide using holographic dynamic gratings. Tris(8-quinolinolato)aluminum (Alq) as a host and 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) as a guest emitter were dispersed in poly(N-vinyl carbazole) (PVCz) matrix. Emission of both the TE(0) and the TM(0) modes was measured. Effective energy transfer from PVCz to DCM through Alq assisted in the reduction of the threshold of laser emission. The threshold of 38 nJ/pulse was measured for first-order lasing and that of 53 nJ/pulse for second-order lasing.