LONGITUDINALLY 2-PHOTON PUMPED LEAKY WAVE-GUIDE DYE FILM LASER

Longitudinally two-photon pumped (TPP) and frequency-upconverted cavit y lasing is achieved in a planar leaky waveguide configuration which u tilizes a dye-doped polymer film coating on the surface of an optical glass prism, The TPP lasing dye is 4-dimethylamino-N-methylstilbazoliu m tosylate (DAST) that has been extensively studied as a second-order nonlinear optical material. The spectral, temporal, and spatial struct ures as well as the output-input characteristics of the TPP cavity las ing were measured using a similar to 170-mu m-thick film with a simila r to 2.4-mm pump depth, The leaky waveguide lasing was featured by a n early single transverse-mode and five axial-modes structure. In our pr eliminary study, the net conversion efficiency from the absorbed 1064- nm pump pulse energy to the output similar to 607-nm upconverted cavit y lasing energy was found to be similar to 0.65%. However, this effici ency can be considerably increased by further optimizing the system pa rameters.