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Spiniform phase-encoded metagratings entangling arbitrary rational-order orbital angular momentum
Kun Huang1,2,3, Hong Liu2, Sara Restuccia4
1Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore.
Light, Science & Applications
|March 7, 2019
Summary
Researchers developed a novel metadevice to generate arbitrary rational-order orbital angular momentum (OAM) beams. This breakthrough enables new possibilities for quantum entanglement and optical applications.
Area of Science:
- Optics and Photonics
- Quantum Information Science
Background:
- Quantum entanglement involving integer and fractional orbital angular momentum (OAM) is established.
- Generating arbitrary rational-order OAM beams has been a significant challenge, limiting exploration of their entangled states.
Purpose of the Study:
- To introduce an effective strategy for generating arbitrary rational-order OAM beams.
- To enable the study of quantum entanglement between arbitrarily defined OAM states.
Main Methods:
- A single metadevice with a bilaterally symmetric grating and aperture was designed.
- The metadevice utilizes a spiniform phase to create dynamically controllable OAM values across a rational range.
- Distributed singularities allow for theoretically unlimited increases in average OAM, differing from traditional fork gratings.
Main Results:
- Demonstrated the generation of optical beams with continuously varying rational-order OAM values.
- Showcased quantum coincidence using rational-order OAM-superposition states with low cross-talk.
- Confirmed the potential for probing unexplored quantum entanglement niches.
Conclusions:
- The novel metagrating provides a pathway for creating and manipulating arbitrary rational-order OAM beams.
- This advancement opens doors for complex microparticle manipulation, high-dimensional quantum entanglement, and enhanced optical communication.
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