Study of the temperature dependence of the absorbance of platinum by measuring the damping of a surface electromagnetic wave and the nature of a squeezed wave

摘要

The temperature dependence of the damping coefficient alpha of a surface electromagnetic wave (SEW) on a platinum mirror has been experimentally measured. The SEW was excited by laser radiation (lambda = 10.6 mu m) on a diffraction grating from which the first order of diffraction propagated along the surface of the mirror. In the temperature range 20- 110 degrees C, the temperature coefficient of damping of the SEW is obtained as beta=d alpha/dT= (18 +/- 2) X 10(-4) cm(-1) degrees C-1. It is obtained from the data of these measurements that dA/dT= 2.7 x 10(-5) C-1, where A is the absorbance of platinum. At the same time that the SEW was excited, excitation of a volume near-surface wave (NSW) on the diffraction grating was observed. propagating from the grating at an angle of 2.5 degrees to the surface of the mirror. It is shown that the appearance of an NSW, also called a squeezed wave, is associated with divergence of the laser radiation. (C) 2006 Optical Society of America.