Measurement of the Intensity-Dependent Refractive Index Using Complete Spatio-Temporal Pulse Characterization

Abstract

We use complete spatio-temporal characterization of an ultrashort pulse to study self-phase modulation and other propagation effects in a sample of SF59 optical glass. The goal of this work is to perform accurate experimental measurements of the optical parameters of material samples. From the measured dependence of the self-induced phase shift on the transverse coordinate, we deduce a value of the coefficient n2 of the intensity-dependent refractive index that is in good agreement with previous measurements. We also observe that the spectrum of the transmitted pulse can be explained only approximately in terms of the solution to the nonlinear Schrödinger equation.

Generation and Characterization of Attosecond Pulses

“…In the process of investigating the process of transfer to modulation by means of EIT, we uncovered some subtle features of the nature of the nonlinear optical response that were reported in several publications (Agarwal and Rzazewski and Boyd, 2004;. We also developed new techniques for the characterization of the nonlinear optical response of materials to ultrashort laser pulses (Piredda et al 2005). Furthermore, we performed some studies aimed at determining the stability of laser beams propagating through nonlinear optical materials .…”

Ultrashort Pulse Characterization

“…Figure 3.3 demonstrates the general principle of how to determine the dynamics of a nonlinear interaction. By measuring the full space-time field for both the incoming pulse and the modulated pulse after the interaction, the extra degrees of freedom can provide improved precision and accuracy for determining the dynamics of the process [23]. Such an experiment can even track specific dynamics of interest in the measured data that cannot be identified by measuring the temporal evolution alone [24].…”

“…23 Spectral and temporal reconstructions; the intensity of the line reflects the probability that the phase or intensity has the corresponding value. Spectral intensity and phase (a).…”

Electric Field Measurement of Femtosecond Time-Resolved Four-Wave Mixing Signals in Molecules

“…In these experiments, the phase shift acquired by the probe pulse at different time delays after the pump pulse in gas-phase targets is measured in a single-shot. Other experiments have measured the modification of ultrashort pulses due to propagation in solid nonlinear media by completely measuring the ultrashort pulse [13,14]. Here, we use the spectral interferometry technique of TADPOLE [15], which is capable of measuring ultra-weak, ultrashort pulses down to the zeptojoule level, to completely measure the real-time varying electric field of a DFWM nonlinear signal, as a function of time delay between the interacting pulses, in carbon dioxide molecules.…”