Creating high dimensional time-bin entanglement using mode-locked lasers
  We present a new scheme to generate high dimensional entanglement between two photonic systems. The idea is based on parametric down conversion with a sequence of pump pulses generated by a mode-locked laser. We prove experimentally the feasibility of this scheme by performing a Franson-type Bell test using a 2-way interferometer with path-length difference equal to the distance between 2 pump pulses. With this experiment, we can demonstrate entanglement for a two-photon state of at least dimension D=11. Finally, we propose a feasible experiment to show a Fabry-Perot like effect for a high dimensional two-photon state. 
Hugues de Riedmatten, Ivan Marcikic, Hugo Zbinden and Nicolas Gisin   (GAP-optique, University of Geneva, Switzerland)