Description:
University of Oregon Researchers: Michael Raymer, Dileep Reddy
Patent: US10,871,699 issued on 12/22/2020 (UO-18-26)
All-Optical Multiplexer and De-multiplexer for Temporal Modes of Electromagnetic Radiation using Nonlinear Optical Cavities and Shaped Laser Pulses.
Technology Background/Definition of Problem:: A quantum pulse gate can be understood as a device that can unitarily and deterministically operate on a single temporal mode (TM) component of an arbitrary pulsed optical input, while simultaneously ensuring zero cross-talk or contamination from any orthogonal TMs of the optical input. However, practical examples of such devices do not exist, as the only known implementation of a QPG, i.e. temporal mode interferometry, as disclosed in D. V. Reddy & M. G. Raymer, arXiv:1710.06736 (2017), and references therein, are limited by substantial footprints. Accordingly, a need remains for a quantum pulse gate without such limitations.
Temporal modes (TM) are a new basis for storage and retrieval of quantum information in states of light. A full TM manipulation toolkit would include a practical quantum pulse gate (QPG), which is a device that unitarily maps any given TM component of the optical input field onto a different, easily separable subspace or degree of freedom. An ideal QPG must “separate” the selected TM component with unit efficiency, whilst avoiding crosstalk from orthogonal TMs. Prior to the present work, all attempts at implementing QPGs in pulsed-pump traveling-wave systems have been unable to satisfy both conditions simultaneously. This is due to a known selectivity limit in processes that rely on spatio-temporally local, nonlinear interactions between pulsed modes traveling at independent group velocities. This limit is a consequence of time ordering in the quantum dynamical evolution, which is predicted to be overcome by coherently cascading multiple stages of low-efficiency, but highly TM- discriminatory QPGs. Multi-stage interferometric quantum frequency conversion in non-linear waveguides was first proposed for precisely this purpose.
Our Technology Solution: TM-nonselective cascaded frequency conversion, also called optical Ramsey interferometry, has recently been demonstrated with continuous-wave (CW) fields. Here, we present the first experimental demonstration of TM-selective optical Ramsey interferometry and show a significant enhancement in TM selectivity over single-stage schemes.
Applications: Optical signal processing, optical computing, photonics, communications.