Isolated Attosecond Pulses Generated Directly from a Femtosecond Chirped Pulse Amplifier*

Using a generalized version of double optical gating, we produced single isolated attosecond pulses with 2 mJ, 25 fs driving lasers directly from a multi-pass Chirped Pulse Amplifier. Through attosecond streaking, we characterized isolated 160 attosecond pulses with 170 pJ pulse energy. By varying the CE phase of the 25 fs driving lasers, the XUV spectrum exhibited a unique 2$\pi $ periodicity indicating the robustness of the sub-cycle gating. Spectral shaping inside the amplifier is implemented to reduce the laser pulse duration for improving the conversion efficiency from NIR to XUV photons. The GDOG technique will allow many labs to generate single attosecond pulses of XUV photons directly from an amplifier which should help further expand the field of attosecond science.