ABSTRACT
Techniques for measuring small optical absorptions have been reviewed previously [3,5]. We will restrict our discussion to those few techniques having special rele vance to polymers in the visible and near-infrared range (200-2500 nm). This wavelength region is of interest for most electrooptic applications. Below, more conventional techniques will be considered first and their limitations will be out lined. Then, the special technique of photothermal deflection spectroscopy will be introduced.