  Wavelength scaling law for the yield of high-order harmonic emission is
theoretically examined for excited state atoms which are optically prepared by
simultaneously exposing to an extreme ultraviolet pulse at the resonant
wavelength and an infrared pulse at a variable wavelength in the range of
0.8\mum-2.4\mum. Numerical simulations are performed based on the
three-dimensional time-dependent Schrodinger equation (3D TDSE) for Ne and H.
We confirm that the harmonic yield follows a \lambda^-{4-6} scaling with the
single fundamental driving laser pulse; whereas for the optically prepared
excited state atoms, a \lambda^-{2-3} scaling for the harmonic yield is
revealed.
