Observations on the coupling channel of two mutually incoherent beams without internal reflection in BaTiO3

Abstract A new scheme of mutually-pumped phase conjugator that works not relying on the internal reflection has been demonstrated experimentally in both one BaTiO 3 crystal and two separated BaTiO 3 crystals. These new phase conjugators differ from the well known double phase-conjugate mirror in that a channel coupling two incident beams has been observed and shared photorefractive holograms with two or more interaction regions in the crystal have to be formed. Thus, it is also demonstrated that coupling channels of two incident beams can be formed not only with internal reflections inside the crystal but also without internal reflection.