title: Four-wave-mixing interferometer.
abstract: We have developed a new method of determining in time both the real and the imaginary parts of third-order nonlinear-optical coefficients. In this method the phase-conjugated four-wave-mixing signal beam interferes with one of the transmitted pump beams. By comparing the interference pattern with that of a known reference, we are able to determine the real and the imaginary parts of the third-order optical nonlinearity for an unknown sample. The real and the imaginary parts can also be separated when one incoming beam is delayed. We apply this method to a bis-thienyl polyene molecule containing five conjugate double bonds and find that the hyperpolarizability is (gamma1111) = (-2.5 - 0.17i) x 10(-30) esu.
authors.forename: N
authors.initials: N
authors.lastname: Tang
authors.forename: J P
authors.initials: JP
authors.lastname: Partanen