Organic semiconductor distributed feedback (DFB) laser as excitation source in Raman spectroscopy.

As an application of organic semiconductor distributed feedback (DFB) lasers we demonstrate their use as excitation sources in Raman spectroscopy. We employed an efficient small molecule blend, a high quality resonator and a novel encapsulation method resulting in an improved laser output power, a reduced laser line width and an enhanced power stability. Based on theses advances, Raman spectroscopy on selected substances was enabled.

Intermediate high index layer for laser mode tuning in organic semiconductor lasers.

We modified the optical properties of organic semiconductor distributed feedback lasers by introducing a high refractive index layer consisting of tantalum pentoxide between the substrate and the active material layer. A thin film of tris-(8-hydroxyquinoline) aluminium doped with the laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylamino-styryl)-4H-pyran was used as the active layer. By varying the intermediate layer thickness we could change the effective refractive index of the guided laser mode and thus the laser wavelength.

Nanostructuring of organic-inorganic hybrid materials for distributed feedback laser resonators by two-photon polymerization.

With two-photon absorption induced polymerization arbitrary three dimensional nano- and microstructures can be patterned directly into photoresists. We report on the fabrication of a low threshold organic semiconductor distributed feedback laser using the technique of two-photon absorption induced polymerization. A surface grating with 400 nm periodicity and 40 nm height modulation was fabricated by two-photon absorption induced polymerization in the organic-inorganic hybrid material ORMOCER.

Organic semiconductor distributed feedback laser fabricated by direct laser interference ablation.

We use a pulsed, frequency tripled picosecond Nd:YAG laser for holographic ablation to pattern a surface relief grating into an organic semiconductor guest-host system. The resulting second order distributed feedback lasers exhibit laser action with laser thresholds being comparable to those obtained with resonators structured by standard lithographic techniques. The details of the interference ablation of tris-(8-hydroxyquinoline) aluminum (Alq(3)) doped with the laser dye 4- dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) are presented and discussed.