Self-referencing spectral interferometry for measuring ultrashort optical pulses

This paper describes a novel self-referencing interferometric method for me asuring the time-dependent intensity and phase of ultrashort optical pulses . The technique, spectral phase interferometry for direct electric-field re construction (SPIDER), measures the interference between a pair of spectral ly sheared replicas of the input pulse. Direct (noniterative) inversion of the interferogram yields the electric field of the input pulse without ambi guity. The interferogram, which is solely a function of frequency, is resol ved with a spectrometer and recorded with a slow detector. Moreover, the ge ometry is entirely collinear and requires no moving components. This paper describes in detail the principle of operation, apparatus, and calibration of SPIDER and gives experimental examples of reconstructed pulses.