Interferometric auto-correlator using third-order nonlinearity

摘要

Interferometric auto-correlation is obtained using third-order (. chi.. sup.(3)) nonlinearities. The nonlinear signal is separated from the linear interferometric response in order to extract information about the amplitude and the chirp of the ultrashort pulses. In one technique, cross- polarized beams are provided to eliminate the linear response. In another technique, electronic filtering is used. Electronic filtering provides substantial reduction of cost, size and complexity over conventional second harmonic generator crystals.