Adaptive self-aligning, bi-directional interconnection using double phase conjugation in Rh:BaTiO 3

Abstract

The results of an experimental demonstration of a very efficient adaptive interconnection between two low power lasers, using a double phase-conjugate mirror (DPCM) in Rh:BaTiO 3 are presented. Using low power incident beams, high phase conjugate reflectivity (∼120%) and, simultaneously, high coupling transmission efficiency (∼50%) of the double phase conjugation process have been measured. After subtracting the losses in the crystal, this diffraction efficiency corresponds to an almost complete deflection of one input laser beam into the direction of the other one. We compare our experimental results on phase conjugate reflectivity and coupling transmission efficiency with analytical predictions of DPCM and find they are in agreement. The build-up time of the interconnection channel was measured taking into account the competition of DPCM with self-pumped phase conjugation. The robustness of the interconnection to out-of-plane angular changes of the direction of one of the input beams is demonstrated. The influence of the laser beam modulation on the interconnection efficiency is studied. We show that the interconnection efficiency is very good even at very strong modulation of the input beams.