In 1986, an International Symposium on Monitoring of Gaseous Pollut- ants by Tunable Diode Lasers was organized by the Fraunhofer-Institut fuer Physikalische Messtechnik in Freiburg, FRG, and held at this institution on November 13-14, 1986. The papers presented at that occasion extensively covered the applications of tunable diode laser spectroscopy (TDLS) to the analysis of trace and exhaust gases together with the latest improvements brought to the tech- niques used. It was generally consented by the participants that meetings of this kind are of major importance and should take place on a regular basis. The organizers were thus encouraged to plan a Second International Sympo- sium on Monitoring of Gaseous Pollutants by Tunable Diode Lasers which was held two years later on October 17-18, 1988, again in Freiburg. In addi- tion to the main subjects treated in the first Symposium, the Scientific Programme this time presented a session on the development of lead chalco- genide lasers. Once more, only a limited attention was given to applica- tions in high resolution molecular spectroscopy.
In order to complete the update, sessions on components and techniques were included in the Pro- gramme. As for the previous Symposium, some space was also given to alter- native optical techniques. This time, in particular contributions on laser photoacoustic detection were included.