Single-shot measurement of the carrier-envelope phase through observation of the self-referencing spectral interferometry

The carrier-envelope phase (CEP) of amplified laser pulses generated by a chirped-pulse-amplification (CPA) system was measured. Single-shot measurement of the CEP was conducted using spectral interferometry (SI) between the white light continuum and its second harmonic. Group delay of the spectrum was assumed to be stable. The SI signals were analyzed using Fourier transforms and a filtering technique. The data was used to calculate the relative phase and relative group delay between the fundamental and the SH components. The difference of the relative phase between two pulses was found to be wavelength independent.