TY - JOUR
T1 - Highly Efficient Broadband Multiplexed Millimeter-Wave Vortices from Metasurface-Enabled Transmit-Arrays of Subwavelength Thickness
AU - Jiang, Zhi Hao
AU - Kang, Lei
AU - Hong, Wei
AU - Werner, Douglas H.
N1 - Funding Information:
This work was funded by the Natural Science Foundation of Jiangsu Province under Grant No. BK20170687, the Natural Science Foundation of China (NSFC) under Grant No. 61627801, the Fundamental Research Funds for Central Universities of China under Grant No. 3204007201, and the Penn State Materials Research Science and Engineering Center (MRSEC), Center for Nanoscale Science, under NSF Grant No. DMR-1420620. Partial support from the Penn State University John L. and Genevieve H. McCain endowed chair professorship is also gratefully acknowledged.
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/6/8
Y1 - 2018/6/8
N2 - Structured electromagnetic waves carrying nonvanishing orbital angular momentum (OAM) have recently opened up alternative frontiers in the field of wave physics, holding great promise for a wide range of potential applications. By leveraging geometric phases originating from spin-to-orbital interactions, spin-dependent wave phenomena can be created, leading to a more versatile realm of dispersionless wave-front manipulation. However, the currently available transmissive vortex-beam generators suffer from a narrow bandwidth, require an optically thick device profile, or are limited by a low efficiency, severely restricting their integration into systems and/or widespread usage for practical applications. We present the design methodology and a physical analysis and complete experimental characterization of a class of millimeter-wave Pancharatnam-Berry transmit-arrays with a thickness of about λ0/3, which enables highly efficient generation and separation of spin-controlled vortex beams over a broad bandwidth, achieving an unprecedented peak efficiency of 88% for a single vortex beam and 71% for dual vortex beams. The proposed transmit-array, which is capable of providing two-dimensional OAM multiplexing and demultiplexing without normal-mode background interference, overcomes all previous roadblocks and paves the way for high-efficiency electromagnetic vortex-beam generation as well as other wave-front-shaping devices from microwave frequencies to optical wavelengths.
AB - Structured electromagnetic waves carrying nonvanishing orbital angular momentum (OAM) have recently opened up alternative frontiers in the field of wave physics, holding great promise for a wide range of potential applications. By leveraging geometric phases originating from spin-to-orbital interactions, spin-dependent wave phenomena can be created, leading to a more versatile realm of dispersionless wave-front manipulation. However, the currently available transmissive vortex-beam generators suffer from a narrow bandwidth, require an optically thick device profile, or are limited by a low efficiency, severely restricting their integration into systems and/or widespread usage for practical applications. We present the design methodology and a physical analysis and complete experimental characterization of a class of millimeter-wave Pancharatnam-Berry transmit-arrays with a thickness of about λ0/3, which enables highly efficient generation and separation of spin-controlled vortex beams over a broad bandwidth, achieving an unprecedented peak efficiency of 88% for a single vortex beam and 71% for dual vortex beams. The proposed transmit-array, which is capable of providing two-dimensional OAM multiplexing and demultiplexing without normal-mode background interference, overcomes all previous roadblocks and paves the way for high-efficiency electromagnetic vortex-beam generation as well as other wave-front-shaping devices from microwave frequencies to optical wavelengths.
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U2 - 10.1103/PhysRevApplied.9.064009
DO - 10.1103/PhysRevApplied.9.064009
M3 - Article
AN - SCOPUS:85048464287
SN - 2331-7019
VL - 9
JO - Physical Review Applied
JF - Physical Review Applied
IS - 6
M1 - 064009
ER -