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We give a topical review in the area of highly luminescent organic materials and their application in solid-state lasers. The progress in conjugated semiconducting polymers is highlighted as these new materials are now established as a novel class of solid-state laser active media. The milestones of recent research results are described together with the technological developments towards electrically driven organic lasers and devices.

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Electron micrograph of a surface of PVBT after UV irradiation and subsequent liquid-phase modification with 1-pyrenemethylamine. The bar represents 10 lm.

A styrene copolymer of 4-vinylbenzyl thiocyanate (PST-co-VBT) was employed as recording material for optical interference patterns with periods Λ < 1 μm. Using lower intensity laser irradiation (4 mJ cm-2, λ = 266 nm), refractive index gratings were produced in PST-co-VBT by an UV-induced photoisomerization SCN → NCS. Subsequent modification of the patterns with gaseous amines yielded surface relief gratings via the formation of derivatives of thiourea. Laser irradiation with higher pulse energies (7 mJ cm-2, λ = 266 nm) directly produced surface relief gratings via laser ablation (modulation depth 30 nm). Also these gratings were reactive toward amine reagents and allowed a selective functionalization of the grooves of the relief (“reactive gratings”). Under selected conditions, a doubling of the grating frequency was achieved by postexposure modification with gaseous amines. Optically inscribed gratings in PST-co-VBT were employed as optical resonators for distributed feedback (DFB) lasing. With a laser dye (DCM) dissolved in PST-co-VBT, optically pumped DFB laser action was observed after inscribing index and relief gratings. The pumping threshold for lasing I th was 250 nJ cm-2 at λ = 532 nm.