Vectorial Solitary Waves in Media with a Second-Order Nonlinearity

Abstract

During the last years the interest in solitary-wave effects in quadratically nonlinear media has increased rapidly. Bright, dark and grey solitary waves were found in the case of scalar second harmonic generation (SHG) where two photons of the fundamental wave create one photon of the second harmonic [1, 2]. In contrast, all investigations of the vectorial or so-called type II SHG (two photons of two different fundamental waves create one photon of the second harmonic) concentrated on cw-operation only. Interesting effects like phase insensitive transistor-like action, polarization switching or high nonlinearly induced phase changes were demonstrated [3, 4]. Thus it should be worthwhile to look for solitary waves in vectorial SHG too. In this system the energy imbalance between the two fundamental waves is a new conserved quantity during propagation. Thus, comparing with scalar SHG we expect to find a two-parameter family of solitary wave solutions.