We report a 10-Hz, highly efficient, widely tunable (from the visible
to the IR), broadband femtosecond optical parametric generator and opt
ical parametric amplifier (OPA) in BBO, LBO, and CBO crystals pumped b
y the frequency-doubled output of a regeneratively amplified Ti:sapphi
re laser at 400 nm. The output of the system is continuously tunable f
rom 440 nm to 2.5 mu m with a maximum overall efficiency of similar to
25% at 670 nm and an optical conversion efficiency of more than 36% i
n 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 o
f the OPA, such as the optical efficiency, the bandwidth, the pulse du
ration, and the group velocity mismatch between the signal and the idl
er and between the seeder and the pump, are investigated. The results
provide useful information for optimization of the design of the syste
m. (C) 1998 Optical Society of America.