Abstract

It is the key point for the interaction of powerful femtosecond pulses with solid targets to use pedestal free pulses with extremely short rise time. Besides, excimer amplifiers can deliver more energy if a few femtosecond pulses delayed by 1 nsec are amplified (so-called multiplexing). Commonly such pulses are summed directly on the target choosing the proper delay for each pulse. Consequently one can de-multiplexed simply the intensities of the pulses. For picosecond pulses it was proposed to de-multiplex using SRS process [1]. In this paper we show that Stimulated Raman Amplification (SRA) in the molecular gases of terawatt femtosecond light pulses could fulfil all the three goals mentioned above, i.e. it provides from a few 1 J pulses the single pedestal-free short-rise-time pulse with up to 70% efficiency. Moreover this pulse in most cases will be shorter as compared to the initial ones - its duration could be less than 100 fsec.

© 1996 IEEE