Improved performance of optical phased arrays assisted by transparent graphene nanoheaters and air trenches |
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| Authors: | Yubing Wang Lei Liang Yongyi Chen Peng Jia Li Qin Yun Liu Yongqiang Ning Lijun Wang |
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| Affiliation: | State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 P. R. China, |
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| Abstract: | In this paper, high-performance optical phased arrays (OPAs) assisted by transparent graphene nanoheaters and air trenches have been designed and simulated. By directly locating graphene nanoheaters on silicon waveguides, heating efficiency is enhanced by 62.96% compared to conventional structures with 1 μm SiO2 overlays, and is further enhanced by a factor of 200% by the presence of air trenches. Thanks to the high thermal conductivity of graphene, a record-high operation speed on the order of 200 kHz is realized. Power consumption for π phase shift is 4.65 mW, approximately half of that of the state-of-the-art OPAs. By introducing air trenches, thermal crosstalk is significantly reduced, resulting in an enlarged fill factor. In addition, a novel beam steering scheme in the θ direction is proposed. By applying a 30 mW heating power, a temperature gradient along antennas is generated and beam steering of 2.3° is achieved, satisfying applications such as long-range collision avoidance for autonomous driving.Improved performances of optical phased arrays have been achieved assisted by graphene nanoheaters and air trenches. |
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