Propagation and self-pumped phase conjugation of femtosecond laser pulses in BaTiO_3

Abstract

We investigate the properties of propagation and self-pumped phase conjugation (SPPC) of 90-fs laser pulses at 450 nm in BaTiO3. Femtosecond SPPC in BaTiO3, both in air and in immersion oil, is explored; it is demonstrated that femtosecond self-pumped phase-conjugate pulses are generated from all crystallographic faces of BaTiO3 in immersion oil. We measure the duration of the pulses after propagation and SPPC by using electric field cross correlation. The duration of SPPC increases as the incident angle increases. Because of the partial compensation of the negative angular dispersion, the self-pumped phase-conjugate pulse undergoes a total dispersion smaller than that of the transmitted pulse. By managing the angular dispersion of the femtosecond phase conjugator, we can control the total dispersion and thus the duration of the self-pumped phase-conjugate pulses. The experimental results agree with the theoretical simulations.