Compression of the spectrum of picosecond ultrashort pulses

The feasibility of compressing the spectrum of ultrashort pulses in fibre-optic time-compression devices was demonstrated experimentally. A spectral compressor of picosecond pulses, consisting of an improved grating compressor and a single-mode fibre waveguide, was developed and tested. Spectral compression by a factor of 2.3 was achieved for ultrashort pulses representing the second harmonic of an Nd : YAG laser with passive mode locking. This result was in good agreement with the theory.