Optical study of plasmons in Tl2Ba2Ca2Cu3O10

The spectral functions of Tl2Ba2Ca2Cu3O10 thin films have been determined accurately from combined reflectance and spectroellipsometric measurements. The plasmon spectrum of Tl2Ba2Ca2Cu3O10 consists of an optic plasmon at about 1.2 eV and a broad band of acoustic plasmons. The latter is revealed by the characteristic quadratic frequency dependence of the loss function, Im(-1)=2, for Latin small letter h with stroke 1 eV. © 1991 The American Physical Society.