Towards high-capacity quantum communications by combining wavelength- and time-division multiplexing technologies

Optical communication systems are able to send the information from one user to another in light beams that travel through the free space or optical fibers, therefore how to send larger amounts of information in smaller periods of time is a long term concern, one promising way is to use multiplexing of photon's different degrees of freedoms to parallel handle the large amounts of information in multiple channels independently. In this work, by combining the wavelength and time division multiplexing technologies, we prepare a multifrequency mode time bin entangled photon pair source at different time slots by using four wave mixing in a silicon nanowire waveguide, and distribute entangled photons into 3 time by 14 wavelength channels independently, which can significantly increase the bit rate compared with the single channel systems in quantum communication. Our work paves a new and promising way to achieve a high capacity quantum communication and to generate a multiple photon nonclassical state.