Abstract

Femtosecond mid-infrared pulses represent an important tool for investigating fundamental processes such as intersubband transition dynamics in quantum wells, hole dynamics in semiconductors, and relaxation of vibrational modes in molecules. Midinfrared pulses have previously been obtained by difference frequency mixing with either a laser and high power amplifier based system,¹ >2 or with two synchronously modelocked picosecond lasers.³ In both cases, the sources are relatively complex. We report here the generation and characterization of femtosecond mid-infrared pulses obtained by direct difference frequency mixing of the two wavelength pulses from a single cavity two color femtosecond Ti:sapphire laser.⁴

© 1994 Optical Society of America