Planar integrated metasurfaces for highly-collimated terahertz quantum cascade lasers.
We report planar integration of tapered terahertz (THz) frequency quantum cascade lasers (QCLs) with metasurface waveguides that are designed to be spoof surface plasmon (SSP) out-couplers by introducing periodically arranged SSP scatterers. The resulting surface-emitting THz beam profile is highly collimated with a divergence as narrow as ~4° × 10°, which indicates a good waveguiding property of the metasurface waveguide. In addition, the low background THz power implies a high coupling efficiency for the THz radiation from the laser cavity to the metasurface structure. Furthermore, since all the structures are in-plane, this scheme provides a promising platform where well-established surface plasmon/metasurface techniques can be employed to engineer the emitted beam of THz QCLs controllably and flexibly. More importantly, an integrated active THz photonic circuit for sensing and communication applications could be constructed by incorporating other optoelectronic devices such as Schottky diode THz mixers, and graphene modulators and photodetectors.
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
Guozhen
G
Liang
National Research Council, Bldg. M-50, 1200 Montreal Rd, Ottawa, Ontario K1A0R6, Canada.
Emmanuel
E
Dupont
1] National Research Council, Bldg. M-50, 1200 Montreal Rd, Ottawa, Ontario K1A0R6, Canada [2] Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, Ontario N2L3G1, Canada.
Saeed
S
Fathololoumi
Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, Ontario N2L3G1, Canada.
Zbigniew R
ZR
Wasilewski
Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, Ontario N2L3G1, Canada.
Dayan
D
Ban
Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075, Singapore.
Hou Kun
HK
Liang
Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075, Singapore.
Ying
Y
Zhang
Department of Applied Physics, Hong Kong Polytechnic University, Kowloon, Hong Kong.
Siu Fung
SF
Yu
School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, UK.
Lianhe H
LH
Li
School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, UK.
Alexander Giles
AG
Davies
School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, UK.
Edmund H
EH
Linfield
Key Laboratory of Artificial Structures and Quantum Control, Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China.
Hui Chun
HC
Liu
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
Qi Jie
QJ
Wang