
426 Femtosecond Pulse Amplification
fact that the gain is essentially unsaturated until the pumping process stops. The
latter is responsible for the shaping of the trailing edge of the signal pulse. With
the onset of saturation (Region II) the pulse duration increases, a tendency which
becomes more pronounced with significant GVD.
7.6. OPTICAL PARAMETRIC CHIRPED PULSE
AMPLIFICATION (OPCPA)
The idea of optical parametric chirped pulse amplification (OPCPA) is to
replace the laser gain media of a CPA system [21], (cf. Section 7.4), by a non-
linear crystal. Amplification by stimulated emission is substituted by parametric
amplification of the signal pulse