Self-referencing spectral interferometry for measuring ultrashort optical pulses

TLDR

SPIDER measures the interference between spectrally sheared replicas of an ultrashort pulse to reconstruct its electric field. This work introduces a self‑referencing SPIDER variant that measures the time‑dependent intensity and phase of ultrashort optical pulses and details its principle, apparatus, calibration, and experimental demonstrations. The method records a frequency‑only interferogram with a spectrometer and a slow detector, then applies a direct, noniterative inversion to retrieve the pulse’s electric field without ambiguity. The geometry is fully collinear, requires no moving parts, and the technique successfully reconstructs pulses in experimental demonstrations.

Abstract

This paper describes a novel self-referencing interferometric method for measuring the time-dependent intensity and phase of ultrashort optical pulses. The technique, spectral phase interferometry for direct electric-field reconstruction (SPIDER), measures the interference between a pair of spectrally sheared replicas of the input pulse. Direct (noniterative) inversion of the interferogram yields the electric field of the input pulse without ambiguity. The interferogram, which is solely a function of frequency, is resolved with a spectrometer and recorded with a slow detector. Moreover, the geometry 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.