Abstract

A cascaded χ⁽²⁾ : χ⁽²⁾ nonlinearity has recently re- ceived considerable attention as a possible way to obtain large nonlinear phase shifts that can be order of mag- nitude larger than those obtainable from the best available third-order nonlinear materials [1]. This remarkable phase shift can exist only if a phase-matching condition for the second harmonic generation (SHG) is approximately satisfied.

© 1996 IEEE