We investigated the structures induced in polysilane and polysilane coated thermoplastic bis-phenol A type epoxy (Epoxy) and poly(methyl methacrylate) (PMMA) films by irradiation of near-infrared (NIR) femto-second laser pulse. Long stripe-shaped structures with approximately 200-400 mum length was induced in polysilane bulk. Thin polysilane layer coated Epoxy and PMMA films showed photo-sensitive effect on the formation of stripe-shaped structures in PMMA and Epoxy, whereas no structures were induced in uncoated PMMA and Epoxy films. An ensemble of stripe-shaped structures worked as a diffraction grating. This photo-sensitive effect has potential application to grating structures in optical polymeric fiber (OPF). (C) 2003 Elsevier Science B.V. All rights reserved.