Need refs. re ellipsometry

 Dear Colleagues;
      I require information relatng to the use of ellipsometry for the quanti-
 fication of biomass accumulating as a biofilm on a thin surface.  If anyone
 has had any experience with this technique, or knows of references describing
 this methodology, I would be grateful if you would contact me.
 Sincerely,
 (Dr.) S. Shapiro
 Inst. f. orale Mikrobiol. u. allg. Immunol.
 Zent. f. Zahn-, Mund- u. Kieferheilkd. der Univ. ZH
 Plattenstr. 11
 Postfach
 CH-8028 ZH 7
 Internet: toukie-: at :-zui.unizh.ch
 FAXnr: ( ... + 1) 261'56'83