Raman spectroscopy in polymeric thin film optical waveguides. 1. Polarized measurements and orientational effects in two-dimensional films

Thin films of polymeric materials often show two-dimensional (2D) orientation depending on the conditions of sample preparation. This ordering has been studied by polarized Raman spectroscopy in which the incident laser light was coupled into thin, transparent films (1-4 μm) of semicrystalline and amorphous polymers deposited on Pyrex substrates forming an asymmetric slab waveguide. This experimental configuration allows propagation (in the waveguide) of modes with different incident polarizations and, in combination with polarization analysis of the scattered light, enables detection of anisotropic orientation in the film. © 1984 American Chemical Society.