The request to organize under its patronage at Poitiers in 1998 a Symposium entitled "Advanced Optical Methods and Applications in Solid Mechanics" by the International Union of Theoretical and Applied Mechanics (I.U.T.A.M.) was well received for the following two reasons. First, for nearly 20 years no Symposium devoted to optical methods in solids had been organized. Second, recent advances in digital image processing provided many new applications which are described in the following. We have the honour to present here the proceedings of this Symposium. st th The Symposium took place from august 31 to September 4 at the Institut International de la Prospective in Futuroscope near Poitiers. A significant number of internationally renowned specialists had expressed their wish to participate in this meeting. The Scientific Committee proposed 16 general conferences and selected 33 regular lectures and 17 poster presentations. Papers corresponding to posters are not differentiated in the proceedings from those that were presented orally. It is worth noting that a total of 80 participants, representing 16 countries, registered for this symposium.. The Scientific Committee deserves praise for attracting a significant number of young scientists, both as authors and as participants. Let us add our warm acknowledgements to Professor J.W. Dally and to Professor A.S. Kobayashi who, throughout the symposium preparation time, brought us valuable help.

In 1976, the International Union of Theoretical and Applied Mechanics (I.U.T.A.M.) agreed to hold a 1979 Symposium on "Optical Methods in Mechanics of Solids" at the University of Poitiers, France. The Labaratory of Mechanics of Solids at the University of Poitiers, a research team associated with the French National Center for Scientific Research (Centre National de la Recherche Scientifique, C.N.R.S.) was in charge of the organization. The symposium was held at the Ecole Nationale Superieure de Mecanique et d'Aerotechnique (E.N.S.M.A.), from the lOth to the 14th of September. We have the honour of presenting here the proceedings of this symposium. This initiave, taken by I.U.T.A.M., was based on the conviction that the time was favourable to point out in the vast domain of experimental methods in mechanics of solids the considerable benefits of the new techniques that became available through the use of the properties of laser radiation. Our experience has shown the validity of this point of view. A significant number of internationally renowned specialists had, in fact, manifested the wish to participate in this meeting and to be invited to present a paper. For instance, the Scientific Committee, after examining 71 proposed papers, selected for presentation 21 short communications (20 minutes of presentation) in addition to 24 regular communications (35 minutes of presentation) .