Application of nonlinearities of metals in ultrashort pulse measurements

Summary form only given. Recently, a new type of very fast femtosecond incoherent frequency-degenerate optical nonlinearity has been reported in bulk metallic gold. This encouraged us to examine the potential application of metals as nonlinear media in optical autocorrelators. Below we describe the use of metal nonlinearity in an autocorrelator, which offers the potential for femtosecond pulse-length measurements over a very wide wavelength range in the visible and infrared. For the recovery of the intensity autocorrelation function we used polarization-sensitive interactions of two pulses reflected from a metallic mirror.