Abstract

Nonlinear optical interactions in waveguides have attracted considerable interest in the past few years. Various classes of materials have been investigated for this purpose. Of these, optically nonlinear polymers have been the focus of intensive research [1]. Their merits render them attractive for use in the development of optoelectronic devices. Quasi-phasematching is a versatile technique for second-order nonlinear processes. The phase-velocity mismatch between interacting waveguide modes at frequencies ω_i (i = 1,2,3) is compensated for by a spatial modulation of the material nonlinearity with a period corresponding to the coherence length [2,3]. Active-passive hybrid waveguides combine the high optical quality of glass waveguides with the strong nonlinearity of poled polymers. Here, the guided modes interact via the evanescent field. For sum frequency (SF) generation in isotropic materials the phase mismatch is large, i.e. the coherence length is only a few microns, which increases by at least two orders of magnitude upon utilizing the mode dispersion of the waveguide [4].

© 1995 Optical Society of America