title: Spatial domain interactions between ultraweak optical beams.
abstract: We have observed spatial interactions between two ultraweak optical beams that are initially collinear and nonoverlapping. The weak beams are steered towards each other by a spatially varying cross-Kerr refractive index waveguide written by a strong laser beam in a three-level coherently prepared atomic medium. After fusing together, the combined beam shows controllable phase-dependent behaviors. This is the first observation of solitonlike interactions between weak beams and can be useful for all-optically tunable beam combining, switching, and gating for weak photonic signals.
authors: Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors: Utsab
authors: U
authors: Khadka
authors: Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors: Jiteng
authors: J
authors: Sheng
authors: Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA and Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
authors: Min
authors: M
authors: Xiao