Design of zigzag folded inversion-stacked AlGaAs waveguides for ultra-compact wavelength converters.

We have proposed and designed zigzag-folded U-shaped waveguides to realize highly efficient wavelength conversion with an extremely small footprint. Extreme high efficiencies are achieved with a combination of modal phase matching and 4¯ quasi phase matching in inversion-stacked AlGaAs/Alox waveguides. Numerical simulations reveal that the conversion efficiency of second harmonic generation pumped at 1.55 μm as high as 12000 %W-1 can be achieved in an 8.0-mm-long AlGaAs/Alox waveguide that is folded up into a small domain of 0.8×0.6 mm2 area. A phase matching signal bandwidth of difference frequency generation, 29 nm, covers 83 % of the telecommunication C band.