IN THIS ISSUE: Femtosecond Lasers: Key to the Measurement of Ultrafast Processes in Semiconductors and Molecules /2 (According to C. L. Tang, Cornell professor of electrical engineering, faster electronic devices are among the technological benefits made possible by new laser techniques.) ... Lasers for Ultrasensitive Detection of Trace Chemicals /7 (How do fuels burn? Terrill A. Cool, professor of applied and engineering physics, explains how tunable dye lasers can provide information about the dynamics of hydrocarbon combustion and other technologically important chemical reactions.) ... Tunable Infrared Lasers Based on Color Centers /12 (Research on a remarkable and useful kind of laser is described by Clifford R. Pollock, assistant professor of electrical engineering.) ... Acousto-Optics for Process Control /18 (A remotely controlled infrared spectroscopic sensor that can be installed in a smokestack to provide fast analysis of emission gases is described by George J. Wolga, professor of electrical engineering and applied physics.) ... Register /22 ... Vantage /30 ... Faculty Publications /32