We propose what is, to our knowledge, a novel method of generating tunable narrow-bandwidth picosecond pulses in which the chirp of equally stretched pump and signal is canceled by difference-frequency mixing. The effect of the group-velocity mismatch on the output pulse bandwidth is analyzed. The method is proved experimentally by generation of pulses of 3.3-cm<sup>−1</sup> bandwidth and 10-ps duration in a type I β barium borate crystal, starting from 1-ps pulses.
© 1999 Optical Society of America
(190.4970) Nonlinear optics : Parametric oscillators and amplifiers
(320.1590) Ultrafast optics : Chirping
(320.5540) Ultrafast optics : Pulse shaping
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
G. Veitas and R. Danielius, "Generation of narrow-bandwidth tunable picosecond pulses by difference-frequency mixing of stretched pulses," J. Opt. Soc. Am. B 16, 1561-1565 (1999)