Control of the single-order harmonic generation by changing the laser parameters of two-color pulse

Abstract We theoretically investigate the control of the single-order harmonic generation by changing the laser parameters of two-color pulse. Four important results have been found. For instance, (1) as the controlling chirp changes from the down-chirp to the up-chirp, the generation of the single-order harmonic can move to the lower harmonic order. (2) As the main pulse duration increases, the larger order single harmonic can be found. While, as the controlling pulse duration increases, the multi-orders harmonic enhancements can be found instead of the single-order harmonic enhancement. (3) As the main laser intensity increases, the larger order single harmonic can be obtained. While, as the controlling laser intensity increases, the multi-orders harmonic enhancements are obtained. (4) With the increase of the wavelength of the main pulse, the lower order single harmonic can be found. While, as the controlling laser wavelength increases, the single-order harmonic is disappeared. Finally, through analyzing the harmonic emission process, the reasonable explanation of the single-order harmonic control is given.