Efficient second harmonic conversion efficiency through one-dimensional coupled resonator poled nonlinear optical waveguide

Abstract

In this paper, the second harmonic generation in finite size one-dimensional coupled resonator poled nonlinear optical waveguide has been investigated. To calculate the conversion efficiency, fundamental and second harmonic wave propagation among two proposed structures, we use the transfer matrix method. In the designed nonlinear photonic crystal structure, the linear and nonlinear optical parameters are both periodically modulated, and thus the second harmonic generation efficiency can be several orders of magnitude larger than in a conventional quasi-phase-matched nonlinear structure with the same sample length. In fact, due to the presence of a photonic band gap in a slow wave system, the density of states of the electromagnetic fields is large at the photonic band edge and photonic defect modes, and thus the group velocity is small, and the local field is enhanced. All these factors contribute to significant enhancement of the nonlinear optical interactions.