Ultrashort-pulse generation in excimer lasers by fast mode locking using electrooptic deflector

A novel method for ultrashort-pulse (USP) generation in excimer lasers employing fast mode locking with the use of an electrooptic deflector (EOD) is investigated numerically. In this method, a USP is formed by a train of very short high-contrast-ratio transmission windows produced in a cavity by a modulator composed of an EOD and a diaphragm. The potential of this method and fundamental properties of USP generation with its use are demonstrated taking a KrF laser as an example. It is shown that the application of the EOD driven with both sine and square wave of voltage enables one to obtain high-contrast-ratio light pulses of duration in the range 1-10 ps at the gain duration of only 50-100 ns. The pulses produced with this method are two orders of magnitude shorter than those attainable with conventional mode locking. The method is capable of being an efficient way for USP generation also in other short-gain-duration lasers.