Variable-time-delay optical coherent transient signal processing

A technique is proposed and experimentally demonstrated that achieves simul taneous optical pattern waveform storage and programmable time delay for co ntinuous real-time signal processing by use of optical coherent transient t echnology. We achieve variable-time-delay and broadband signal processing b y frequency shifting of two chirped programming pulses, the chirp rate of o ne being twice that of the other, without using brief reference pulses and without changing the timing of the programming sequence. We demonstrate the technique experimentally in Tm3+:YAG at 5 K for 40-MHz chirps by performin g temporal signal convolution with true-time delays that vary over a 250-ns range. (C) 1999 Optical Society of America OCIS codes: 070.6020, 060.1660, 190.2640, 320.1590.