Typically, thin films present an intrinsic stress greater than the bulk one and in graded reflectivity mirror (GRM) production such intrinsic stress can cause coating delamination owing to the presence on the coating of one or more variable thickness layers. In this work, the mechanical stability of GRM working at a wavelength of 10.6 mu m(CO2 laser) for two different Gaussian indexes (n=2 and n=5) was investigated. Both GRM are composed of four layers (ZnSe and BaF2 materials) with a variable thickness layer embedded in the structure (second layer). The employment of BaF2 buffer layer deposited on the variable thin film in order to avoid the detachment of the coating at the edge of the variable layer, where its thickness becomes zero, was investigated.
|Pages (from-to)||491 - 496|
|Number of pages||6|
|Journal||Pure and Applied Optics: Journal of the European Optical Society Part A|
|Publication status||Published - 1994|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
Scaglione, S., Flori, D., & Caneve, L. (1994). Influence of thin film thermal stress on a variable thickness layer in graded reflectivity mirror production. Pure and Applied Optics: Journal of the European Optical Society Part A, 3(4), 491 - 496. . https://doi.org/10.1088/0963-9659/3/4/010