Lasing action in optically written two-dimensional DFB gratings

Gratings for laser applications in poly(styrene-co-4-vinylbenzyl-thiocyanate) (PST-co-VBT) are being optically recorded by deep UV lithography (lambda = 266nm). The gratings writing configuration is based on interference patterning of this novel-type holographic material. Using lower intensity laser irradiation, refractive index gratings are produced in PST-co-VBT by an UV induced photoisomerization SCN-NCS. Laser irradiation with higher pulse energies directly produces surface relief gratings via laser ablation. Holographically recorded structures of dye-doped PST-co-VBT (DCM:PST-co-VBT) are designed for second order distributed feedback (DFB) operation resulting in low threshold organic lasers devices. 2D DFB lasers with two perpendicular gratings having different grating periods are investigated with respect to tuneable DFB lasing.