We propose a quantum information framework that employs field-orthogonality of single-photon temporal modes. The three requirements–generation of resource states, the targeted and efficient manipulation of TMs, and their detection and characterization–can be fulfilled with current technology.
In quantum communications applications, information can, in principle, be encoded with an alphabet that goes beyond 0 and 1. It can be shown that a higher dimensional alphabet provides greater information capacity and improved security [1] . Temporal modes (TMs) provide such a high-dimensional alphabet and form an appealing framework for quantum information science [2] . Additionally, as opposed to transverse spatial or orbital angular momentum modes, TMs are compatible with spatially single-mode systems.
Abstract We review the concepts of temporal modes (TMs) in quantum optics, highlighting Roy Glauber’s crucial and historic contributions to their development, and their growing importance in quantum information science. TMs are orthogonal sets of wave packets that can be used to represent a multimode light field. They are temporal counterparts to transverse spatial modes of light and play analogous roles—decomposing multimode light into the most natural basis for isolating statistically independent degrees of freedom. We discuss how TMs were developed to describe compactly various processes: superfluorescence, stimulated Raman scattering, spontaneous parametric down conversion, and spontaneous four-wave mixing. TMs can be manipulated, converted, demultiplexed, and detected using nonlinear optical processes such as three-wave mixing and quantum optical memories. As such, they play an increasingly important role in constructing quantum information networks.