Broadband uniform-efficiency OAM-mode detector

Science Advances, vol. 11, pp. eadq7201

Abstract

The high-dimensional basis of orbital angular momentum (OAM) has several added and unique advantages for photonic quantum technologies compared to the polarization basis, which is only two-dimensional. However, one of the major roadblocks in implementing OAM-based applications with their full potentials is the absence of an ideal OAM-mode detector. Despite the plethora of efforts in the last three decades, currently, there is no OAM detector that can detect a broad OAM-mode spectrum, has uniform detection-efficiency over all the modes, measures the true spectrum, and works for an arbitrary quantum state without the need for any previous information. Here, we experimentally demonstrate just such an OAM detector. We report detection of pure and mixed OAM states with fidelities more than 98% and with measurement times of only a few minutes for dimensionalities up to 100. We expect our work to substantially boost the OAM-based photonic quantum technology efforts.

Authors 3

1. Suman Karan corresponding

   Indian Institute of Technology Kanpur

   Affiliation as printed

   Department of Physics, Indian Institute of Technology Kanpur, Kanpur, UP 208016, India

2. Martin P. Van Exter Aachen Huygens-Kamerlingh Onnes Laboratory

   Leiden University

   Affiliation as printed

   Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, Netherlands

3. Anand K. Jha corresponding

   Indian Institute of Technology Kanpur

   Affiliation as printed

   Department of Physics, Indian Institute of Technology Kanpur, Kanpur, UP 208016, India