Noncollinear type II second harmonic generation in Al(0.3)Ga(0.7)As/Al2O3 one-dimensional photonic bandgap structure

We have designed a one-dimensional photonic bandgap crystal to obtain perfect phase-matching conditions for noncollinear type II quadratic processes. The realized sample was 15 periods of Al (0.3) Ga (0.7) As/Al 2 O 3 , for a total length of 3.5um. Noncollinear type II phase-matching was obtained at 1510nm. We have experimentally verified the band structure characteristic as well as its perfect phase-matching for the noncollinear type II parametric process. Indeed, noncollinear type II second harmonic generation was obtained for the first time in a PBG crystal1. The experiment demonstrated that the breaking of symmetry, which is artificially induced in such a structure, and the field resonance effect give rise to a relatively efficient second harmonic generation even using a naturally isotropic material (AlGaAs). In fact, we report a nonlinear effective coefficient of the sample equal to (52±12) pm/V.