We demonstrate that solarization occurs in glass substrates during thin-film deposition and that it induces high absorption near the surface of the substrate. Solarization has been observed especially in ion-plating deposition. We show that the solarization of the substrate is caused by electromagnetic radiation emitted from the material to be evaporated. The radiation is due to the energy losses of the heating beam of electrons (bremsstrahlung radiation). Multicomponent glasses such as BK7 are much more sensitive to solarization than fused-silica substrates. The photoinduced high absorption can be partially reversed by thermal annealing.
© 1998 Optical Society of America
Original Manuscript: May 21, 1997
Revised Manuscript: October 2, 1997
Published: April 1, 1998
Ludovic Escoubas, Alexandre Gatto, Gérard Albrand, Pierre Roche, and Mireille Commandré, "Solarization of glass substrates during thin-film deposition," Appl. Opt. 37, 1883-1889 (1998)