Intense circularly polarized attosecond pulse generation from relativistic laser plasmas using few-cycle laser pulses

National Natural Science Foundation of China [11304331, 11174303, 11374262]; National Basic Research Program of China [2013CBA01504]; Fundamental Research Funds for Central Universities; Munich Center for Advanced Photonics (MAP); DFG [Transregio TR18]; EWe have investigated the polarization of attosecond light pulses generated from relativistic few-cycle laser pulse interaction with the surface of overdense plasmas using particle-in-cell simulation. Under suitable conditions, a desired polarization state of the generated attosecond pulse can be achieved by controlling the polarization of the incident laser. In particular, an elliptically polarized laser pulse of suitable ellipticity can generate an almost circularly polarized attosecond pulse without compromising the harmonic generation efficiency. The process is thus applicable as a new tabletop circularly-polarized XUV radiation source for probing attosecond phenomena with high temporal resolution. (C) 2016 Optical Society of Americ