ABSTRACT
In investigations and applications of nonlinear optical (NLO) polymers, besides obtaining a thorough understanding of their nonlinear behavior, it is necessary to characterize their linear optical properties. These are the real and imaginary parts of the index of refraction as a function of wavelength and the concomitant dielectric function in the optical region. The real part (n) is the standard index of refraction, which can be anisotropic; the imaginary part (K) is directly related to the optical absorbance and it can be dichroic. In this Chapter, we will explain and discuss the various methods for determining these optical constants of a NLO polymer in thin film form, the common configuration for device applications. Although we will be addressing exclusively x<2l materials, many of the techniques also apply to x<3l materials.
