UV-laser-assisted modification of the optical properties of polymethylmethacrylate

Polymethylmethacrylate (PMMA) has been irradiated by UV-laser light with di fferent wavelengths (193, 248, 308 nm) in order to modify photolytically it s refractive index. The photoinduced chemical reactions at the polymer surf ace have been investigated by QMS, XPS and FTIR and the mechanism of the st ructure modification has been clarified. It was shown that depending on the experimental conditions, an increase of the refractive index in the modifi ed zones could be achieved. The controllable local increase of the refracti ve index was used to prepare passive integrated-optical waveguides in PMMA chips. (C) 2000 Elsevier Science B.V. All rights reserved.