title: Quasi-phase-matching of only even-order high harmonics.
abstract: High harmonic spectrum of a quasi-monochromatic pump that interacts with isotropic media consists of only odd-order harmonics. Addition of a secondary pump, e.g. a static field or the second harmonic of the primary pump, can results with generation of both odd and even harmonics of the primary pump. We propose a method for quasi-phase matching of only the even-order harmonics of the primary pump. We formulate a theory for this process and demonstrate it numerically. We also show that it leads to attosecond pulse trains with constant carrier envelop phase and high repetition rate.
authors.forename: Tzvi
authors.initials: T
authors.lastname: Diskin
authors.forename: Oren
authors.initials: O
authors.lastname: Cohen