Graphene-based photodetectors have attracted significant attention for high-speed optical communication due to their large bandwidth, compact footprint, and compatibility with silicon-based photonics platform. Large-bandwidth silicon-based optical coherent receivers are crucial elements for large-capacity optical communication networks with advanced modulation formats. Here, we propose and experimentally demonstrate an integrated optical coherent receiver based on a 90-degree optical hybrid and graphene-on-plasmonic slot waveguide photodetectors, featuring a compact footprint and a large bandwidth far exceeding 67 GHz. Combined with the balanced detection, 90 Gbit/s binary phase-shift keying signal is received with a promoted signal-to-noise ratio. Moreover, receptions of 200 Gbit/s quadrature phase-shift keying and 240 Gbit/s 16 quadrature amplitude modulation signals on a single-polarization carrier are realized with a low additional power consumption below 14 fJ/bit. This graphene-based optical coherent receiver will promise potential applications in 400-Gigabit Ethernet and 800-Gigabit Ethernet technology, paving another route for future high-speed coherent optical communication networks.
Polarization multiplexing technology is widely adopted for increasing the capacity in optical communication systems. Especially, silicon‐based integrated polarization division multiplexing (PDM) optical receivers with large bandwidth therein play an important role, which are crucial for on‐chip large‐capacity optical interconnection. Here, a silicon‐based PDM optical receiving chip is enabled by two‐dimensional grating couplers and graphene‐on‐plasmonic slot waveguide photodetectors. Utilizing the advantages of the designed focusing two‐dimensional grating couplers and plasmonic‐slot‐waveguide‐enhanced graphene–light interaction, the optical receiving chip is achieved with an ultra‐small footprint, a bandwidth exceeding 70 GHz and a reception of PDM signals in a line rate of 128 Gbit s−1 non‐return‐to‐zero and 224 Gbit s−1 four‐level pulse‐amplitude‐modulation at 1550 nm, accompanied by the bit error rates lower than the KP4 forward error correction threshold and 15% soft‐decision forward error correction threshold, respectively. Comparing with receiving the single‐polarization state, simultaneous receiving dual‐polarization state introduces about 1 dB additional power penalty because of inter‐polarization crosstalk. The graphene‐plasmonic PDM optical receiving chip can greatly improve the line rate of the system, showing its unique advantages of small footprint, high speed, large bandwidth, low crosstalk and complementary metal–oxide–semiconductor compatibility, which can be potentially used in the next generation silicon‐based high‐speed optical communication.
Photo-mixing with its advantages of ultra-large bandwidth and precise tunability has emerged as an important technique for terahertz (THz) wave generation. Recently, graphene photodetectors exhibiting a large bandwidth are expected to further boost the development of integrated THz emitters. Here, we fabricate a sub-THz emitter based on a large-bandwidth silicon–plasmonic graphene (SPG) photodetector integrated with a broadband rounded bow-tie THz antenna. The SPG sub-THz emitter is experimentally demonstrated to emit sub-THz waves with a radiation spectrum from 50 to 300 GHz. A maximum sub-THz emission power of 5.4 nW is obtained at 145 GHz with only 3 mW input light power. The SPG sub-THz emitter can be fabricated by a CMOS-compatible process, which offers enormous opportunities for its use in a variety of THz applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.