Optimized conditions for intense isolated attosecond pulse generation

Summary form only given. Harmonics reflected from an oscillating plasma mirror doesn´t subject to the limitation of maximum applied laser intensity and can thus exploit the benefit of state-of-the-art terawatt and petawatt laser technology, enabling a route to extreme bright attosecond light sources. When the pulse duration decreases to two laser cycles, intensity gating can lead to an isolated attosecond pulse. This harmonic generation process features a high nonlinearity, resulting in a high conversion efficiency. In our recent work, an efficiency higher than 10^-4 was measured in the wavelength range 17nm to 80nm by using a 28fs Ti:Sapphire laser operating at a peak intensity of 4×10¹⁸ W/cm² (a≈1.5).