TY - JOUR
T1 - Hybrid optical antenna with high directivity gain
AU - Bonakdar, Alireza
AU - Mohseni, Hooman
PY - 2013/8/1
Y1 - 2013/8/1
N2 - Coupling of a far-field optical mode to electronic states of a quantum absorber or emitter is a crucial process in many applications, including infrared sensors, single molecule spectroscopy, and quantum metrology. In particular, achieving high quantum efficiency for a system with a deep subwavelength quantum absorber/emitter has remained desirable. In this Letter, a hybrid optical antenna based on coupling of a photonic nanojet to a metallo-dielectric antenna is proposed, which allows such efficient coupling. A quantum efficiency of about 50% is predicted for a semiconductor with volume of ̃?3/170. Despite the weak optical absorption coefficient of 2000 cm-1 in the long infrared wavelength of ̃8 μm, very strong far-field coupling has been achieved, as evidenced by an axial directivity gain of 16 dB, which is only 3 dB below of theoretical limit. Unlike the common phased array antenna, this structure does not require coherent sources to achieve a high directivity. The quantum efficiency and directivity gain are more than an order of magnitude higher than existing metallic, dielectric, or metallo-dielectric optical antenna.
AB - Coupling of a far-field optical mode to electronic states of a quantum absorber or emitter is a crucial process in many applications, including infrared sensors, single molecule spectroscopy, and quantum metrology. In particular, achieving high quantum efficiency for a system with a deep subwavelength quantum absorber/emitter has remained desirable. In this Letter, a hybrid optical antenna based on coupling of a photonic nanojet to a metallo-dielectric antenna is proposed, which allows such efficient coupling. A quantum efficiency of about 50% is predicted for a semiconductor with volume of ̃?3/170. Despite the weak optical absorption coefficient of 2000 cm-1 in the long infrared wavelength of ̃8 μm, very strong far-field coupling has been achieved, as evidenced by an axial directivity gain of 16 dB, which is only 3 dB below of theoretical limit. Unlike the common phased array antenna, this structure does not require coherent sources to achieve a high directivity. The quantum efficiency and directivity gain are more than an order of magnitude higher than existing metallic, dielectric, or metallo-dielectric optical antenna.
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U2 - 10.1364/OL.38.002726
DO - 10.1364/OL.38.002726
M3 - Article
C2 - 23903124
AN - SCOPUS:84881183084
SN - 0146-9592
VL - 38
SP - 2726
EP - 2728
JO - Optics Letters
JF - Optics Letters
IS - 15
ER -