Self-activated Nd:Ba2NaNb5O12 optical super-lattices: Micro characterization and non-collinear laser light generation

Czochralsky grown Nd³⁺-ion doped barium sodium niobate (Ba₂NaNb₅O₁₂, “banana”) optical super-lattices have been characterized by a combination of chemical etching, optical microscopy, micro-Raman and micro-photoluminescence experiments. The presence of ferroelectric domains, induced during growth process, is accompanied by a periodic modulation of Nd³⁺-ion concentration as well as by a small lattice distortion. When Nd³⁺-ion laser action at ≈1.06 μm is achieved under 0.808 μm laser diode pumping, the singularities of refractive index caused by opposed ferroelectric domains lead to non-collinear intra-cavity propagation.