Resonator mirrors for x-ray and XUV lasers are commonly made of nanometric layer stacks of two different materials. In these applications the crucial nondestructive evaluation tasks are the determination of thermal transport properties and thermal deformation of the mirrors. In this paper we report our recent progress in thermal diffusivity determination of Ag/W and Al/W multilayer stacks by mirage detection of laser induced thermal waves. The results are compared with those of single layer samples of component materials determined by the same method. A noteworthy advantage of the mirage method is that it measures primarily the in- plane heat flow in the metal film to obtain its thermal properties and it does not need the ultra- high modulation frequencies when applied to ultra-thin films as do other photothermal techniques.

Date Published: 24 June 1993
PDF: 14 pages
Proc. SPIE 1848, 24th Annual Boulder Damage Symposium Proceedings -- Laser-Induced Damage in Optical Materials: 1992, (24 June 1993); doi: 10.1117/12.147410

Published in SPIE Proceedings Vol. 1848:
24th Annual Boulder Damage Symposium Proceedings -- Laser-Induced Damage in Optical Materials: 1992
Harold E. Bennett; Lloyd L. Chase; Arthur H. Guenther; Brian Emerson Newnam; M. J. Soileau, Editor(s)