Advances in carrier‐envelope phase stabilization of grating‐based chirped‐pulse amplifiers

Grating‐based chirped pulse amplifiers are the cornerstone of high‐power femtosecond lasers. The amplification of carrier‐envelope phase stable pulses in such lasers has only been realized within the last few years. Currently, the state‐of‐the‐art in this endeavor is utilizing the change in grating separation in the stretcher or compressor. The carrier‐envelope phase drift can be reduced to the 160 mrad RMS level and the carrier‐envelope phase can be swept in a 2 π range. The effects of laser pulse energy stability on the f‐to‐2f measurement of the carrier‐envelope phase were found to be significant, with a 1% change in laser energy leading to 160 mrad phase error, showing the need for power‐stable amplified laser systems. The phase‐stabilized pulses from grating‐based chirped amplifiers have been successfully used in attosecond pulse generation with subcycle gating techniques.