Spontaneous four wave mixing (SFWM) is an important way to develop telecom band quantum light sources, which are crucial photonic quantum devices required for fiber-based quantum communications. In this talk, I will introduce our recent progress on four wave mixing (FWM) quantum light sources and their applications on quantum key distribution (QKD) networks. Firstly, some examples will be introduced to show that single photon level FWM provides a complete platform for quantum optics at telecom band. They are 1) hybrid entanglement generation in optical fiber; 2) true single photon stimulated FWM; 3) frequency degenerate polarization entangled Bell state generation by a silicon quantum photonic circuit. Then, I will introduce how to use energy-time entangled photon pairs generated by SFWM to realize a specific QKD protocol, dispersive optics QKD (DO-QKD). Recently, we realized a large scale entanglement-based QKD network based on this protocol.
Wei Zhang received his Bachelor’s degree in 1998 and Ph. D in 2003, respectively, from Electronic Engineering Department, Tsinghua University, China. Then he joined Institute of Information Optoelectronic Technology, Electronic Engineering Department, Tsinghua University. At present, he is a tenured professor of Tsinghua University and the vice director of the Institute of Information Optoelectronic Technology. His research interests include Micro/nano-photonic devices, integrated quantum photonic devices, photonic quantum information technologies, especially quantum communications and quantum imaging.