Photochemical methods were developed to obtain a variation of the refractive index in aromatic polymer surfaces and a change in the photoluminescence characteristics of phenylene-vinylene-based polymers. Films of aromatic polymers, among them polystyrene (PS), poly(2-vinylnaphthalene) (PVN) and derivatives of poly(-phenylene-vinylene) (PPV) were UV irradiated in the presence of gaseous hydrazine (N2H4). The photoreaction led to a strongreduction of the refractive index of the polymers due to a hydrogenation of the aromatic units. In the case of PPV, we observed reductive photobleaching. This new technique was employed to produce photogenerated patterns in PPV. The results are compared to oxidative bleaching.

A styrene copolymer of 4-vinylbenzyl thiocyanate (PST-co-VBT) was employed as recording material for optical interference patterns with periods ∧ < 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 (modulation depth 30 nm). These gratings were also reactive towards amine reagents and allowed a selective functionalization of the grooves of the relief (“reactive gratings”). 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.

Photochemical methods were developed to obtain a variation of the refractive index in aromatic polymer surfaces and a change in the photoluminescence characteristics of phenylenevinylene-based polymers. Films of aromatic polymers, among them polystyrene (PS), poly(2-vinylnaphthalene) (PVN) and derivatives of poly(p-phenylene-vinylene) (PPV) were UV irradiated in the presence of gaseous hydrazine (N2H4). The photoreaction led to a strong reduction of the refractive index of the polymers due to a hydrogenation of the aromatic units. In the case of PPV, we observed reductive photobleaching. This new technique was employed to produce photogenerated patterns in PPV. The results are compared to oxidative bleaching.