@ARTICLE\{IMM2001-0159,
    author       = "O. Bang and J. F. Corney",
    title        = "Asymmetric induced cubic nonlinearities in homogeneous and quasi-phase-matched quadratic materials: signature and importance",
    year         = "2001",
    month        = "dec",
    pages        = "42",
    journal      = "Optics and Photonics News",
    volume       = "12",
    editor       = "",
    number       = "12",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/159-full.html",
    abstract     = "In continuous-wave operation asymmetric induced nonlinearities induce an intensity-dependent phase mismatch that implies a nonzero so-called separatrix intensity, the crossing of which changes the one-period phase shift of the fundamental by Pi , with obvious use in switching applications.We derived a formula for this {QPM-}induced separatrix intensity that corrects earlier estimates by a factor of 5.{3,} and we found the optimum crystal lengths for a flat phase-versus-intensity response on each side of the separatrix"
}