title: Concurrent optical parametric down-conversion in χ(2) nonlinear photonic crystals.
abstract: We experimentally investigated concurrent parametric downconversion processes in a two-dimensional hexagonally poled lithium tantalate crystal. The substantial enhancement of parametric gain was observed when concurrent processes shared a common parametric beam. Both degenerate and nondegenerate concurrent parametric downconversion processes were studied. Analyses of the spatial forms and output angles showed a strong dependence on the working temperature, during which a well-defined beamlike parametric output was observed. Our results will stimulate the design for coherent high-gain generation of multiple parametric beams and also shed light on the compact engineering of path-entanglement with specific spatial forms based on concurrent spontaneous parametric downconversion processes.
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Xu
authors.forename: Y F
authors.initials: YF
authors.lastname: Bai
authors.forename: X W
authors.initials: XW
authors.lastname: Luo
authors.forename: M L
authors.initials: ML
authors.lastname: Zhong
authors.forename: M
authors.initials: M
authors.lastname: Dai
authors.forename: M H
authors.initials: MH
authors.lastname: Lu
authors.forename: S N
authors.initials: SN
authors.lastname: Zhu