Compression and broadening of phase-conjugate pulses in photorefractive self-pumped phase conjugators

Pulse propagation and shaping are investigated in photorefractive self-pump ed phase conjugators in both transmission- and reflection-grating regimes. The dispersion properties of self-pumped phase conjugators are analyzed by taking into account both the grating dispersion and the angular dispersion. The complex transfer functions are obtained by treating the crystal as a l inear dispersive medium. We show that the pulse width as a result of the se lf-pumped phase conjugation is much wider in the reflection regime than in the transmission regime. The experimental results are consistent with the r esults calculated for the transmission-grating regime, indicating that this type grating is the dominant mechanism in the case of a femtosecond self-p umped phase conjugator. (C) 2000 Optical Society of America [S0740-3224(00) 00908-5] OCIS codes: 190.5040, 190.5330, 190.5530, 320.5520.