Enhancing high-order harmonic generation in two-color laser fields: A comparison of single- and two-color schemes

We compare the enhancement of high-order harmonic generation in argon using 800--400 and 800--266~nm laser fields with their optimized single-color counterparts. We observe that the two-color fields generally outperform the single-color 800~nm field by factors of 2 to 3800, depending on the photon energy and generation scheme. From this comparison, we determine which scheme is optimal for each photon energy. We also observe that the divergence of HHG produced by the 800--266~nm laser fields is smaller than that of the other single- and two-color driving fields, perhaps suggesting that the 800--266~nm fields optimize the recombination probability of the so-called ``short" electron trajectories.