We have developed a novel source for the generation of powerful phase-
coherent light pulses. Our setup uses an acousto-optic modulator (AOM)
inside an external high-finesse resonator. By applying a short rf pul
se to the AOM, we dump the cavity and extract a large part of the stor
ed and enhanced power within a short optical pulse and with a controll
able optical phase. In preliminary experiments we reached 100 W of pea
k power in a 15-ns optical pulse. The mutual phase coherence of succes
sive light pulses is demonstrated with a molecular iodine interferomet
er experiment in a cell. (C) 1997 Optical Society of America.