Incoherent light pulses

Motoyoshi Baba, Ying Li, Masahiro Matsuoka

We extend the intensity interference experiments to a pulse envelope measurement of ultrashort incoherent optical pulses. The interfering fields can be mutually incoherent light pulses from independent sources. We show that the pulse envelope or width of ultrashort incoherent light pulses can be measured independently from the coherence time by using a combination of interferometer and two-photon coincidence counter. With this method we have measured the envelope autocorrelation of mutually incoherent femtosecond fluorescence from a solution of Nile Blue in dimethylaniline.

Giuseppe Palumbo, Riccardo Pratesi, Brian L Diffey

M. A. Bouchène, Anne Débarre, J. Keller +2 more

Observation of 0π-pulse formation with incoherent light through field cross-correlation is theoretically and experimentally demonstrated. The experiment illuminates some of the properties of this new incoherent light technique, which is used to analyze the fast temporal variations of the signal. In particular, the technique’s time resolution, signal-to-noise ratio, and sensivity to dispersion are investigated.

Salvatore Carusotto

Andy Francis

Lindsey Van Wagenen

One of the long-standing difficulties in working with intense incoherent light has been the lack of a theory for predicting and explaining experimental results. The diagrammatic theory of Friedberg and Hartmann provides a solution to this problem by allowing one to study the interaction of intense incoherent light and matter with no restrictions on the intensity of the pulses. In the present investigation, two-pulse photon-echo experiments were performed with intense incoherent light in atomic sodium vapor and the results were compared with predictions calculated from the Friedberg-Hartmann diagrammatic theory. The dependence of the echo signal on the intensity of the constituent excitation pulses was studied. The results of this investigation indicate that the two-pulse incoherent photon-echo experimental data are consistent with the calculations obtained from the theory presented in the diagrammatic paper of Friedberg and Hartmann when the atomic relaxation times are included. The two-pulse-echo data show good agreement with the theoretical predictions for the case in which 4T2 = T1 (the atomic and transverse lifetimes, respectively), which represents more of a decay than has been theoretically predicted for the experimental parameters used.