Photopumped organic solid-state dye laser with a second-order distributed feedback cavity

We describe a photopumped distributed feedback (DFB) organic solid-state dy e laser consisting of an active layer containing a low-threshold gain-narro wing dye and an SiO2 DFB cavity based on second-order diffraction. A second -order diffraction grating is easy to fabricate compared with a first-order one having the same Bragg wavelength. When 4,4'-bis(4-(ditolyamino)styryl) biphenyl was used as the laser material, the threshold of the laser was 0.8 kW/cm(2), a low value despite using a low-coupling-coefficient cavity base d on second-order diffraction. This was a result of using a low-threshold g ain-narrowing dye. Laser-light emission from the surface was observed, indi cating that an organic "transverse cavity" surface-emitting laser could be developed using a second-order diffraction grating and a low-threshold gain -narrowing dye.