TY - JOUR
T1 - Generation of Orbital Angular Momentum by a Point Defect in Photonic Crystals
AU - Chen, Menglin L.N.
AU - Jiang, Li Jun
AU - Sha, Wei E.I.
N1 - Funding Information:
This work was supported in part by the Research Grants Council of Hong Kong (Grants No. GRF 716713, GRF 17207114, and GRF 17210815), NSFC (Grant No. 61271158), Hong Kong UGC (Grant No. AoE/P-04/08), AOARD (Grant No. FA2386-17-1-0010), Hong Kong (Grant No. ITP/045/14LP), the Hundred Talents Program of Zhejiang University (Grant No. 188020194231701/208), and HKU Seed Fund 201711159228.
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/7/31
Y1 - 2018/7/31
N2 - As an attractive degree of freedom in electromagnetic (EM) waves, the orbital angular momentum (OAM) enables infinite communication channels for both classical and quantum communications. The exploration of OAM generation inspires various designs involving spiral phase plates, antenna arrays, metasurfaces, and computer-generated holograms. In this work, we theoretically and experimentally demonstrate an approach to producing OAM carrying EM waves by a point defect in three-dimensional (3D) photonic crystals (PCs). Simultaneous excitation of two vibrational-defect states with an elaborately engineered phase retardation generates a rotational state carrying OAM. Through converting guided waves in a line defect to localized waves in a point defect and then to radiated vortex waves in free space, the lowest four OAM-mode emitters, i.e., OAM indices of ±1 and ±2, are successfully realized. This work offers a physical mechanism to generate OAM by PCs, especially when the OAM generation is to be integrated with other designs.
AB - As an attractive degree of freedom in electromagnetic (EM) waves, the orbital angular momentum (OAM) enables infinite communication channels for both classical and quantum communications. The exploration of OAM generation inspires various designs involving spiral phase plates, antenna arrays, metasurfaces, and computer-generated holograms. In this work, we theoretically and experimentally demonstrate an approach to producing OAM carrying EM waves by a point defect in three-dimensional (3D) photonic crystals (PCs). Simultaneous excitation of two vibrational-defect states with an elaborately engineered phase retardation generates a rotational state carrying OAM. Through converting guided waves in a line defect to localized waves in a point defect and then to radiated vortex waves in free space, the lowest four OAM-mode emitters, i.e., OAM indices of ±1 and ±2, are successfully realized. This work offers a physical mechanism to generate OAM by PCs, especially when the OAM generation is to be integrated with other designs.
UR - http://www.scopus.com/inward/record.url?scp=85051468131&partnerID=8YFLogxK
U2 - 10.1103/PhysRevApplied.10.014034
DO - 10.1103/PhysRevApplied.10.014034
M3 - Journal article
AN - SCOPUS:85051468131
SN - 2331-7019
VL - 10
JO - Physical Review Applied
JF - Physical Review Applied
IS - 1
M1 - 014034
ER -