1. R.R.Menzies, M.S.Shumate: Appl. Opt.15, 2080 (1976)
2. C.Jaussaud: Rapport C.E.A. R461 (May 1975)
3. S.O.Kanstad, A.B.Bjerkestrand, T.Lund: J. Phys. E (Sci. Instrum.)10, 998 (1977)
4. I.Comera, C.Jaussaud, A.Charpentier, J.Fouquin: Private communication
5. K.Hotta, K.Inoue, K.Washio: Laser Equipement Development Div., Nippon Electric Co. Ltd. Kawasaki, Japan