Optical Properties of Polystyrene Films in the Far Ultraviolet

Measurements of the optical properties of solid polystyrene in the wavelength range 1100-2300 Å are reported. The real and imaginary parts of the complex index of refraction were determined from transmission measurements on a series of thin films. The absorption spectrum shows a strong peak at 1925 Å plus minor features around 1350 and 2170 Å as well as evidence for a second major peak below 1100 Å. The measured values of the optical constants were used to calculate the complex dielectric constant and the characteristic electron energy-loss function. The latter exhibits a maximum at 6.92 eV which appears to arise primarily from collective excitation effects.