High-yield generation of synchronized picosecond monochromatic pulses using frequency femtosecond chirped pulses

Summary form only given. We demonstrate the efficient generation of synchronized monochromatic pulses in the 5- to 10-ps range, using a femtosecond chirped amplification system. The method relies on the control of the pulse frequency time sweep introduced in a CPA system using the property of symmetry in a type I sum-frequency crystal. We use the output of a chirped amplification system split in two beams, each pulse being partially compressed in a grating-based compressor with strictly opposite chirps and duration tunable from a nanosecond to a few picoseconds. These pulses are then combined at a small angle in a doubling crystal, so that phase matching occurs for the mixing process along the bisecting axis but does not occur for the direct doubling of each pulse. A time-delay line compensates the difference in optical path and allows the frequency of the generated second harmonic to be tuned.