Optically-Based Diagnostics for Gas-Phase Laser Development

In this paper we describe several diagnostics that we have developed to assist the development of high power gas phase lasers including COIL, EOIL, and DPAL. For COIL we discuss systems that provide sensitive measurements of O 2 (a), small signal gain, iodine dissociation, and temperature. These are key operational parameters within COIL, and these diagnostics have been used world-wide to gain a better understanding of this laser system. Recently, we have developed and integrated a similar suite of diagnostics for scaling the EOIL system and will provide examples of current studies. We are also developing diagnostics for the emerging DPAL laser. These include monitors for small signal gain that will provide both a more fundamental understanding of the kinetics of DPAL and valuable data for advanced resonator design. We will stress the application of these diagnostics to realistic laser systems.