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.