Application of the hybrid laser SOFIA for OPCPA pumping

The laser laboratory SOFIA (Solid-State Oscillator Followed by Iodine Amplifiers) started its operation in 2003 as a test facility the laser system PALS (Prague Asterix Laser System). The basic SOFIA project now is the realization of the OPCPA (Optical Parametric Chirped Pulse Amplification) method where the iodine photodissociation laser system serves as a pump. This unique method of the amplification of ultrashort pulses presents a big challenge for the iodine lasers which have a narrow gain bandwidth (∼0.02 nm) and therefore the classical methods of the pulse shortening are not applicable. The main advantage of the gas laser system as a pump for the parametric amplification of ultrashort pulses is a high spatial homogeneity of the pumping beam and a suitable temporal profile. The SOFIA laser system has been built up as a hybrid laser where the oscillator beam is produced in a solid- state optical parametric oscillator (MOPO-HF pumped by the third harmonics of Nd:YAG laser) tuned to 1315 nm (the iodine spectral line) and subsequently amplified in two gaseous iodine amplifiers.