HIGH-REPETITION-RATE NONLINEAR GENERATION OF SYNCHRONIZED FREQUENCY TUNABLE FEMTOSECOND PULSES

Pulses delivered by a high power Ti:sapphire femtosecond oscillator ar e frequency broadened in an optical fiber and subsequently filtered to generate two synchronized frequency tunable femtosecond pulses at a r epetition rate of 76 MHz. The created pulses are transform limited wit h a duration in the range 70-120 fs, and independently tunable over 22 0 nm. The possibilities offered by this source for high sensitivity tw o-color femtosecond spectroscopy are demonstrated in GaAs.