Abstract

We reported recently¹ coherent beam couplings in self-pumping reflection, and transmission in BaTiO₃. We now report the effects of self-pumped phase conjugation on reflection and transmission, and beam couplings using incoherent beams A₁(7.4 mW) and A₂(9.2 mW) from two He-Ne lasers (6328 Å). The crossing angle is 11° with A₁ making 73° with the c-axis. The self-pumped phase conjugate A₁, its transmitted part A₁T₁ after one reflection, and the specular reflection A₁R₁ from the front face are examined along with the subsequent transmission and reflection beams a₁t₂ and a₁r₂. When A₁ is put on, A₁R₁ and A₁R₂ shoot up immediately. A₁ A₁T₁, and A₁T₂ grow up with time and saturate while A₁R₁ and a₁r₂ go down and saturate as A₁ stabilizes. When beam A₂ is also turned on, A₁ comes down, while A₁R₁ and A₁R₂ go up in intensity. However, A₁T₁ comes down while A₁T₂ goes up. These results are explained in terms of contribution of A₁, the cross coupling from Â₂, and the grating erasure effects of A₁ and A₂. The decay of the A₂ couplings in the above beams is much faster here than in the earlier experiments with coherent beams.

© 1989 Optical Society of America