Silicon photonics integrated with graphene provides a promising solution to realize integrated photodetectors operating at the communication window thanks to graphene’s ultrafast response and compatibility with CMOS ...Silicon photonics integrated with graphene provides a promising solution to realize integrated photodetectors operating at the communication window thanks to graphene’s ultrafast response and compatibility with CMOS fabrication process.However, current hybrid graphene/silicon photodetectors suffer from low responsivity due to the weak light-graphene interaction. Plasmonic structures have been explored to enhance the responsivity, but the intrinsic metallic Ohmic absorption of the plasmonic mode limits its performance. In this work, by combining the silicon slot and the plasmonic slot waveguide, we demonstrate a novel double slot structure supporting high-performance photodetection, taking advantages of both silicon photonics and plasmonics. With the optimized structural parameters, the double slot structure significantly promotes graphene absorption while maintaining low metallic absorption within the double slot waveguide. Based on the double slot structure, the demonstrated photodetector holds a high responsivity of 603.92 m A/W and a large bandwidth of 78 GHz. The high-performance photodetector provides a competitive solution for the silicon photodetector. Moreover,the double slot structure could be beneficial to a broader range of hybrid two-dimensional material/silicon devices to achieve stronger light-matter interaction with lower metallic absorption.展开更多
This study constructs a theoretical framework to analyze the impact of local governmentled construction land supply(LGCLS)strategies on urban innovation.It uses data related to 265 cities in China from 2005 to 2019 fo...This study constructs a theoretical framework to analyze the impact of local governmentled construction land supply(LGCLS)strategies on urban innovation.It uses data related to 265 cities in China from 2005 to 2019 for empirical analysis.Its conclusions are as follows.For development stage differences,the impact of LGCLS strategies on urban innovation exhibited an inverted U shape with economic growth.The inflection point occurred when the per capita GDP equaled approximately RMB23,101 in 2008.For regional diferences,the inflection point in eastern China is higher and earlier than that in central and western China;before the inflection point,the positive infuence was more obvious in the central and western regions,whereas after the inflection point,the negative influence was more obvious in the eastern region.For the eastern Yangtze River Delta urban agglomerations and the northwestern resource-based urban agglomerations with relatively high per capita GDP,the negative impact of LGCLS strategies on urban innovation occurred earlier and showed spatial agglomeration characteristics.展开更多
All-optical integrators are key devices for the realization of ultra-fast passive photonic networks, and, despite their broad applicability range(e.g., photonic bit counting, optical memory units, analogue computing, ...All-optical integrators are key devices for the realization of ultra-fast passive photonic networks, and, despite their broad applicability range(e.g., photonic bit counting, optical memory units, analogue computing, etc.), their realization in an integrated form is still a challenge. In this work, an all-optical integrator based on a silicon photonic phase-shifted Bragg grating is proposed and experimentally demonstrated, which shows a wide operation bandwidth of 750 GHz and integration time window of 9 ps. The integral operation for single pulse, inphase pulses, and π-shifted pulses with different delays has been successfully achieved.展开更多
Metasurface made of artificially two-dimensional structured subwavelength-scaled nanostructures gives rise to unprecedented efficient way to realize on-chip all-optical modulation,in both classical regime and quantum ...Metasurface made of artificially two-dimensional structured subwavelength-scaled nanostructures gives rise to unprecedented efficient way to realize on-chip all-optical modulation,in both classical regime and quantum regime.展开更多
基金supports from Innovative Solutions for Next Generation Communications Infrastructure(INCOM project,sponsored by Innovation Fund Denmark)The Center for Silicon Photonics for Optical Communication(SPOC,DNRF123)+3 种基金QUANPIC project sponsored by VILLUM FONDEN(No.00025298)Mid-chip project sponsored by VILLUM FONDEN(No.13367)Independent Research Fund Denmark(No.9041-00333B)Starting Research Fund from the Huazhong University of Science and Technology(No.3004182179)。
文摘Silicon photonics integrated with graphene provides a promising solution to realize integrated photodetectors operating at the communication window thanks to graphene’s ultrafast response and compatibility with CMOS fabrication process.However, current hybrid graphene/silicon photodetectors suffer from low responsivity due to the weak light-graphene interaction. Plasmonic structures have been explored to enhance the responsivity, but the intrinsic metallic Ohmic absorption of the plasmonic mode limits its performance. In this work, by combining the silicon slot and the plasmonic slot waveguide, we demonstrate a novel double slot structure supporting high-performance photodetection, taking advantages of both silicon photonics and plasmonics. With the optimized structural parameters, the double slot structure significantly promotes graphene absorption while maintaining low metallic absorption within the double slot waveguide. Based on the double slot structure, the demonstrated photodetector holds a high responsivity of 603.92 m A/W and a large bandwidth of 78 GHz. The high-performance photodetector provides a competitive solution for the silicon photodetector. Moreover,the double slot structure could be beneficial to a broader range of hybrid two-dimensional material/silicon devices to achieve stronger light-matter interaction with lower metallic absorption.
基金the Humanities and Social Sciences Foundation of Ministry of Education of China(No.22YJC630132)the Natural Science Foundation of Jiangsu Province(No.BK20221026)+1 种基金the National Natural Science Foundation of China(No.42101272)the Natural Science Foundation of Shandong Province(No.ZR2021QD085)。
文摘This study constructs a theoretical framework to analyze the impact of local governmentled construction land supply(LGCLS)strategies on urban innovation.It uses data related to 265 cities in China from 2005 to 2019 for empirical analysis.Its conclusions are as follows.For development stage differences,the impact of LGCLS strategies on urban innovation exhibited an inverted U shape with economic growth.The inflection point occurred when the per capita GDP equaled approximately RMB23,101 in 2008.For regional diferences,the inflection point in eastern China is higher and earlier than that in central and western China;before the inflection point,the positive infuence was more obvious in the central and western regions,whereas after the inflection point,the negative influence was more obvious in the eastern region.For the eastern Yangtze River Delta urban agglomerations and the northwestern resource-based urban agglomerations with relatively high per capita GDP,the negative impact of LGCLS strategies on urban innovation occurred earlier and showed spatial agglomeration characteristics.
基金National Natural Science Foundation of China(NSFC)(61475052,61622502)
文摘All-optical integrators are key devices for the realization of ultra-fast passive photonic networks, and, despite their broad applicability range(e.g., photonic bit counting, optical memory units, analogue computing, etc.), their realization in an integrated form is still a challenge. In this work, an all-optical integrator based on a silicon photonic phase-shifted Bragg grating is proposed and experimentally demonstrated, which shows a wide operation bandwidth of 750 GHz and integration time window of 9 ps. The integral operation for single pulse, inphase pulses, and π-shifted pulses with different delays has been successfully achieved.
文摘Metasurface made of artificially two-dimensional structured subwavelength-scaled nanostructures gives rise to unprecedented efficient way to realize on-chip all-optical modulation,in both classical regime and quantum regime.