Abstract

Second-harmonic (SH) pulse compression in KDP type II phase matching crystal has been shown to be an attractive method of the pulse shortening, starting with pico- and sub­picosecond pulses from the Nd:glass laser^1-3. An inherent feature is that compressed pulses are accompanied by the satellites occurring due to the cascading of second-order processes. It is quite obvious, that if a re-conversion process could be started at proper time, a fundamental frequency pulse, produced by the re-conversion of the SH pulse, may experience a notable shortening. Recently, triggering of the cascaded processes under phase-matching conditions has been shown to be possible by unbalancing of the intensities of o and e-polarized inputs in type II SH generator⁴.

© 1996 IEEE