Abstract

Recent years have witnessed a tremendous progress in the generation of ultra-broadband few-optical-cycle pulses. Accurate characterization of the temporal profile of pulses with such extreme bandwidth and broad frequency tunability poses a severe experimental challenge. Birge et al. [1] introduced two-dimensional spectral shearing interferometry (2DSI); this can be seen as a zero-delay SPIDER and requires the generation of two spectrally sheared replicas of the pulse under test by interaction with ancillary fields. The information on the spectral phase is obtained by acquiring many interference patterns as a function of the delay between the two replicas; exact retrieval of the phase requires very careful calibration of their spectral shear Ω. Traditional techniques to generate the sheared replicas are based on ancillary fields produced by a stretcher and an unbalanced Michelson interferometer: the strong limitation of this arrangement is that it allows only approximate characterization of Ω by indirect measurements [2].

© 2015 IEEE