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-phasematched
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.
