High-Order Harmonic Generation and Quasiphase Matching in Xenon Using Self-Guided Femtosecond Pulses

Abstract : Ultrashort self-guided laser pulses are employed to generate high-order harmonics in noble gases. Interference fringes between fundamental and harmonic waves over several cm reveal a long range longitudinal coherence of the generated harmonics. Quasiphase matching is demonstrated for the third harmonic wave.