A representative photon energy-calibrated CCD camera image taken at temporal overlap of all three pulses is shown in Fig. . The negative absorbance features (blue) observed in the camera image indicate the generation of new XUV light due to wave-mixing emission. The spatial dimension of the camera image is plotted as a function of the angle of divergence relative to the harmonics, which have been translated off of the CCD chip to minimize interreference from onaxis (0 mrad) signals. Note that wave-mixing pathways that incorporate two, time-coincident NIR pulses can emit at both negative and positive divergence angles, depending on the arbitrarily assigned NIR pulse order. Although discrete emission lines can be discerned as a function of photon energy, the wave-mixing features are broad in divergence angle. The angular divergence of these wave-mixing features (Fig. ) primarily reflects the angular spread of the incident XUV beam, but the divergence also may be broadened to lesser extent by additional FWM pathways that emit at similar energies.