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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Continuous-wave laser operation of a dipole antenna terahertz microresonator
AU - Masini, Luca
AU - Pitanti, Alessandro
AU - Baldacci, Lorenzo
AU - Vitiello, Miriam S.
AU - Degl'Innocenti, Riccardo
AU - Beere, Harvey E.
AU - Ritchie, David A.
AU - Tredicucci, Alessandro
PY - 2017/10/6
Y1 - 2017/10/6
N2 - Resonators and the way they couple to external radiation rely on very different concepts if one considers devices belonging to the photonic and electronic worlds. The terahertz frequency range, however, provides intriguing possibilities for the development of hybrid technologies that merge ideas from both fields in novel functional designs. In this paper, we show that high-quality, subwavelength, whispering-gallery lasers can be combined to form a linear dipole antenna, which creates a very efficient, low-threshold laser emission in a collimated beam pattern. For this purpose, we employ a terahertz quantum-cascade active region patterned into two 19-μm-radius microdisks coupled by a suspended metallic bridge, which simultaneously acts as an inductive antenna and produces the dipole symmetry of the lasing mode. Continuous-wave vertical emission is demonstrated at approximately 3.5 THz in a very regular, low-divergence (±10°) beam, with a high slope efficiency of at least 160 mW A â '1 and a mere 6 mA of threshold current, which is ensured by the ultra-small resonator size (V RES/Î" 3 â ‰10 â '2). The extremely low power consumption and the superior beam brightness make this concept very promising for the development of miniaturized and portable THz sources to be used in the field for imaging and sensing applications as well as for exploring novel optomechanical intracavity effects.
AB - Resonators and the way they couple to external radiation rely on very different concepts if one considers devices belonging to the photonic and electronic worlds. The terahertz frequency range, however, provides intriguing possibilities for the development of hybrid technologies that merge ideas from both fields in novel functional designs. In this paper, we show that high-quality, subwavelength, whispering-gallery lasers can be combined to form a linear dipole antenna, which creates a very efficient, low-threshold laser emission in a collimated beam pattern. For this purpose, we employ a terahertz quantum-cascade active region patterned into two 19-μm-radius microdisks coupled by a suspended metallic bridge, which simultaneously acts as an inductive antenna and produces the dipole symmetry of the lasing mode. Continuous-wave vertical emission is demonstrated at approximately 3.5 THz in a very regular, low-divergence (±10°) beam, with a high slope efficiency of at least 160 mW A â '1 and a mere 6 mA of threshold current, which is ensured by the ultra-small resonator size (V RES/Î" 3 â ‰10 â '2). The extremely low power consumption and the superior beam brightness make this concept very promising for the development of miniaturized and portable THz sources to be used in the field for imaging and sensing applications as well as for exploring novel optomechanical intracavity effects.
KW - microresonators
KW - optical antennas
KW - quantum cascade laser
KW - terahertz
KW - whispering-gallery
U2 - 10.1038/lsa.2017.54
DO - 10.1038/lsa.2017.54
M3 - Journal article
AN - SCOPUS:85030664887
VL - 6
JO - Light: Science and Applications
JF - Light: Science and Applications
SN - 2095-5545
IS - 10
M1 - e17054
ER -