Abstract

We present a new technique for measuring pulse temporal profiles at the pico- and femtosecond time scales using a direct real-time method based on the nonlinear- optic Fourier transformation process (NOFT). NOFT is implemented in the spectral compressor, which consists of a dispersive delay line followed by a nonlinear single-mode lightguide [1]. In DDL pulses are stretched experiencing a negative chirp, and in the nonlinear fiber the chirp quenching due to self- or cross- phase modulation (SPM/XPM) leads to spectral narrowing. The accurate chirp quenching results in NOFT: the conversion of temporal information to the spectral domain for both the intensity and the phase of the input wave. So, spectral compressor with a spectrometer can serve as a high temporal resolution optical oscilloscope, and the problem of direct, real-time, high-resolution temporal measurements is reduced to standard spectrometry.

© 1998 IEEE