Kilohertz femtosecond UV-pumped visible beta-barium borate and lithium triborate optical parametric generator and amplifier

Highly efficient, widely tunable, 10-Hz parametric amplifier pumped by frequency-doubled femtosecond Ti:sapphire laser pulses

We report a 10-Hz, highly efficient, widely tunable (from the visible to the IR), broadband femtosecond optical parametric generator and optical parametric amplifier (OPA) in BBO, LBO, and CBO crystals pumped by the frequency-doubled output of a regeneratively amplified Ti:sapphire laser at 400 nm. The output of the system is continuously tunable from 440 nm to 2.5 microm with a maximum overall efficiency of approximately 25% at 670 nm and an optical conversion efficiency of more than 36% in the OPA stage. The effects of the seed beam energy, the type of the crystal and the crystal length, and the pumping energy of the output of the OPA, such as the optical efficiency, the bandwidth, the pulse duration, and the group velocity mismatch between the signal and the idler and between the seeder and the pump, are investigated. The results provide useful information for optimization of the design of the system.

Group-velocity control in the mixing of three noncollinear phase-matched waves

A model of three-wave parametric interactions is presented, in both type I and type II noncollinear phase-matching conditions, in which the group velocities of the interacting pulses are suitably linked to each other. We consider two conditions for group velocities that are significant in the parametric generation/amplification of femtosecond pulses and determine the interaction geometry required to fulfill them in uniaxial crystals. The results are compared with those for collinear phase matching and are used to interpret the behavior of ultrabroadband parametric sources.

Efficient visible femtosecond optical parametric generator and amplifier using tilted pulse-front pumping

Using pulses with tilted pulse fronts to compensate for the group-velocity mismatch in three-wave interactions, we constructed an efficient 400-nm pumped femtosecond collinear typeI phase-matched beta -barium borate optical parametric generator and amplifier. The signal and idler outputs are tunable from 470nm to 2.7 microm and have pulse widths in the range of 100170fs at a 1-kHz repetition rate. A maximum output energy of 6.5 microJ and a total conversion efficiency of more than 15% were achieved.