POLARIZATION BACKWARD-WAVE 4-WAVE-MIXING IN BATIO3-FE USING THE PHOTOVOLTAIC EFFECT

We report the first study to our knowledge of polarization backward-wa ve four-wave mixing in a BaTiO3:Fe crystal and compare the results of our measurements with the calculations performed within the model of p hotovoltaic charge transport. Two identically polarized pump waves and one orthogonally polarized signal wave are sent to a sample in a plan e normal to the crystal's C axis; a phase-conjugate wave with polariza tion identical to that of the signal wave is generated. With a 2-mm-th ick sample a phase-conjugate reflectivity R-pc approximate to 0.01 is reached; for a 1-cm-thick sample, amplified reflection should be possi ble. (C) 1997 Optical Society of America.