Ultrahigh Peak Power Pulses Produced by Chirped Pulse Amplification

Abstract

Chirped Pulse Amplification (CPA)1 allows the amplification of short laser pulses in amplifying media with good storage properties (low transition cross section) like Nd:glass1,2 or Alexandrite.3-4 In these media, straight amplification cannot be performed well, because of the large input flux necessary to reach efficient energy extraction. This condition leads to unacceptable peak powers. To minimize the intensity effects, the pulse is stretched, amplified, and recompressed. This technique allows an efficient energy extraction while maintaining a good beam quality. The intensity is kept below the onset level of small-scale focusing, occurring when values of the B integral are larger than three. We recall that the B integral is given by the expression.