Interferometric hetero-detector phase measurements

Summary form only given. Characterization of ultrashort light pulses is a primary concern of the researcher working with mode-locked lasers. Here we present an improved frequency domain phase measurement (FDPM). This configuration employs only linear passive filters with a nonlinear time integrating detector incorporated to measure a phase-dependent signal. In our setup we used a nonlinear detector operating by two-photon absorption. The signal measured by this detector depends in a nonlinear way on the phase of the spectrum.