Characterization of Ultrashort Optical Pulses in the Few-Cycle Regime Using Spectral Phase Interferometry for Direct Electric-Field Reconstruction

Abstract

Interferometry provides a very sensitive and accurate means to measure the phase of an optical field. It has been applied with great effect in the past few years to measurements of the spectral phase of ultrashort optical pulses. Together with measurement of the pulse spectrum, which may be made simultaneously, this provides complete characterization of single pulses. The conversion of phase to amplitude information that is the hallmark of interferometric measurement makes it very sensitive to small differences in phase and allows robust extraction of the spectral phase from measured data. The key features of spectral phase interferometry that make it useful for pulses in the few-cycle regime are the rapidity of data acquisition and the inversion and insensitivity of the measurement to wavelength-dependent apparatus response. Both of these properties are important for characterizing sources for which the pulseshape fluctuates and the pulses have extremely large bandwidths. In this chapter, we discuss the method of spectral phase interferometry for direct electric-field reconstruction and its application to the measurement of pulses in the sub-10 fs regime.