This study investigates the rapidity with which an optical dye in a solid plastic host irreversibly degrades when it is brightly illuminated by visible light. Specifically, the organic dye cresyl violet perchlorate dispersed in plexiglas was optically excited by a continuous-wave dye laser pumped by an argon-ion laser. After resonantly absorbing and emitting many times, an individual dye molecu...

Four different schemes for the generation of femtosecond input pulses for ArF amplifiers are described. Pulse energies of 100 nJ were obtained with phase-matched frequency mixing of a Raman-shifted frequency-doubled pulse derived from a 537-nm femtosecond dye-laser pulse. Excellent spatial, spectral, and amplitude stability was obtained when a broadband, nanosecond dye laser at 690 nm was used ...

The development of a distributed-feedback dye laser, with a pulse width and a line width of 25 ps and 8.78 pm, respectively, is described. Using this nearly Fourier-transform-limited pulse, we measured the first singlet-excited-state lifetime of 1,2,4-trichlorobenzene. The tunable picosecond dye laser developed herein has a potential for the lifetime measurement and the efficient multiphoton io...

Hydrophobic photostable dye molecules such as perylenes or pyrromethenes were trapped in xerogel matrices. Using these new materials as solid-state dye lasers, we have demonstrated efficient laser operation. Slope efficiencies of up to 30% were obtained in the millijoule output-energy range. Tunabilities of up to 60 nm were observed, and more than 150,000 pulses were emitted by the same spot of...

Photophysical parameters and lasing properties of Coumarin 540A dye molecules are studied in solutions of increasing viscosity, from liquid solutions in 1,4-dioxane to solid solutions in poly~methyl methacrylate!. The fluorescence quantum yield and lasing efficiencies decrease as the viscosity of the solution increases, reflecting the strong influence of the rigidity of the medium on the radiat...

We report on the experimental demonstration of considerable lowering of stimulated luminescence (lasing) threshold in R6G laser dye solution doped with metal agglomerates (Ag, Al, Ni) upon second harmonic of Nd:YAG-laser illumination. Due to strong structural coupling between individual nanoparticles, they may form fractal agglomerates providing an extreme optical pump-field enhancement near th...

We report wide range and reversible tuning of the selective reflection band of a single crystal cholesteric liquid crystal elastomer (CLCE). The tuning is the result of mechanical shortening of the helical pitch achieved by imposing a uniform uniaxial strain along the helical axis. On doping the CLCE sample with a laser dye, we observe lasing from the CLCE in both glassy and rubbery states. By ...

BACKGROUND Purpura-free elimination of telangiectases with a single pass of a pulsed dye laser with a large spot has proved difficult. OBJECTIVE The purpose of this report was to define parameters that achieve single-pass purpura-free telangiectasia reduction. MATERIALS Thirty patients between the ages of 23 and 78 years were treated with a pulsed dye laser with a 10-mm spot and fluences ra...

INTRODUCTION The clinical presentation of morphea varies from localized plaques to generalized eruptions. Its cause remains unknown and medical treatments have often proved unsatisfactory. Studies have previously shown that improvement of hypertrophic scars and fibrotic skin can be achieved with the use of a 585 nm pulsed dye laser (PDL). METHODS A case of plaque-type morphea was treated with...

The successful use of the 585-nm pulsed dye laser for the treatment of hypertrophic scars has been well established over the past decade. Although 5 years ago this treatment option might have been considered as a viable choice only after all other methods failed, it is now generally recognized as an excellent first-line treatment option. Early scar treatment with pulsed dye laser irradiation ef...