Use of nonlinear dynamic spectroscopy in determination of the chirp of picosecond pulses generated in a neodymium phosphate glass laser

A nonlinear dynamic spectrograph with a time resolution of 0.1 psec and a spectral resolution of 0.02 nm was used to determine the chirp of picosecond pulses generated in a neodymium phosphate glass laser emitting at the wavelength of 1.054 µ. A time scan was obtained employing a nonlinear LiIO₃ crystal together with conversion of the investigated radiation to the visible range, where dynamic spectrograms were recorded. It was established that the chirp amplitude increased at the end of a train of pulses to 1.5 nm/psec.