Carrier-Envelope-Phase Dependence of Emission Properties of High-Order Harmonic Generation

The carrier-envelope-phase (CEP) dependence of the emission properties of high-order harmonic generation (HHG) are quantitatively investigated. Calculation shows that a two-cycle laser with CEP of 15° can produce a single energy distribution pulse peaked at 0.94 radian (rad) and spanned 1.29rad with the cutoff energy 2.9Up+Ip and a bandwidth 0.86Up (where Up is the ponderomotive potential of the laser field and Ip is the atomic ionization potential). The CEP dependence of the energy and temporal localizations of the single distribution pulse show interesting 180° periodic structures. These characteristics may be useful in optimizing attosecond x-ray sources and measurements.