Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Exploitation of transverse spatial modes in spontaneous four wave mixing photon-pair sources
Héctor Cruz-Ramírez, Roberto Ramírez-Alarcón, Daniel Cruz-Delgado, Jorge Monroy-Ruz, Erasto Ortiz-Ricardo, Francisco A. Domínguez-Serna, Karina Garay-Palmett, Alfred B. U’Ren
Abstract
We present a source for which multiple spontaneous four-wave mixing (SFWM) processes are supported in a few mode birefringent fiber, each process associated with a particular combination of transverse modes for the four participating waves. Within the weakly guiding regime, for which the propagation modes may be well approximated by linearly polarized (LP) modes, the departure from circular symmetry due to the fiber birefringence translates into orbital angular momentum (OAM) and parity conservation rules, i.e. reflecting elements from both azimuthal and rectangular symmetries. In our source: i) each process is group-velocity-matched so that it is, by design, nearly-factorable, and ii) the spectral separation between neighboring processes is greater than the marginal spectral width of each process. Consequently, there is a direct correspondence between the joint amplitude of each process and each of the Schmidt mode pairs of the overall two-photon state. The present paper covers work presented in Refs.1 and.2