Here,we show that a naphthalenediimide skeleton can facilitate the hierarchical assembly of a derived metal N-heterocyclic carbene(NHC)macrocycle into diverse supramolecular architectures.The macrocycle exhibited solv...Here,we show that a naphthalenediimide skeleton can facilitate the hierarchical assembly of a derived metal N-heterocyclic carbene(NHC)macrocycle into diverse supramolecular architectures.The macrocycle exhibited solvent-dependent supramolecular isomerization,and two polymorphs with different stacking modes grown in DMF and MeCN were obtained.The coprecipitation of the obtained macrocycle and a cuprous bromide anion led to the formation of a tertiary structure.Through the donor-acceptor interactions between the electron-deficient macrocycle and electron-rich pyrene/naphthalene,two cocrystal complexes with different supramolecular systems were successfully fabricated.Moreover,the solid-state structure of the corresponding radical macrocycle unambiguously confirmed the existence of an ordered linear array extending from the discrete mononuclear NHC-Au(Ⅰ)macrocycle via multiple noncovalent interactions.Such a radical NHC-Au(Ⅰ)macrocycle can be readily generated upon a one-electron reduction.展开更多
Coherent passive optical network(PON)is a promising architecture that offers high sensitivity and support for advanced modulation formats.However,fully coherent systems have high complexity and cost,making them unsuit...Coherent passive optical network(PON)is a promising architecture that offers high sensitivity and support for advanced modulation formats.However,fully coherent systems have high complexity and cost,making them unsuitable for cost-sensitive user-end applications.Additionally,in coherent access architectures,the lasers of optical network units(ONUs)in the upstream are typically kept on rather than being switched off to avoid wavelength drift,with the Mach–Zehnder modulators(MZMs)biased at the null point for modulation.However,the limited extinction ratio(ER)of the MZM introduces direct current(DC)leakage,which degrades system performance and limits the number of users the network can support.To address this issue,we design and fabricate the first silicon-photonics-based ultimate-simplified coherent-optics chip for ONU.The simplified transmitter employs a single MZM combined with a high-speed optical switch(OS),while the simplified receiver adopts a hybrid and a standalone photodetector(PD)for coherent detection with Alamouti coding.By integrating the OS,the upstream achieves a maximum ER of 63.93 d B,while the OS switching speed meets the guard interval requirements of PON systems.Compared to a traditional single MZM with a 26 d B ER,our design achieves an additional 37.93 d B improvement,which significantly increases the user capacity in PON systems.Comprehensive experiments were conducted to validate the proposed design.Ultimately,leveraging this ultimate-simplified coherent-optics chip,a 100 Gbps bidirectional transmission was successfully demonstrated with a power budget exceeding 29 d Bm,verifying its feasibility and cost-effectiveness for next-generation coherent optical access networks.展开更多
基金supported by the National Natural Science Foundation of China(22025107)the National Youth Topnotch Talent Support Program of China,the Key Science and Technology Innovation Team of Shaanxi Province(2019TD-007)the Xi’an Key Laboratory of Functional Supramolecular Structure and Materials,and the FM&EM International Joint Laboratory of Northwest University.
文摘Here,we show that a naphthalenediimide skeleton can facilitate the hierarchical assembly of a derived metal N-heterocyclic carbene(NHC)macrocycle into diverse supramolecular architectures.The macrocycle exhibited solvent-dependent supramolecular isomerization,and two polymorphs with different stacking modes grown in DMF and MeCN were obtained.The coprecipitation of the obtained macrocycle and a cuprous bromide anion led to the formation of a tertiary structure.Through the donor-acceptor interactions between the electron-deficient macrocycle and electron-rich pyrene/naphthalene,two cocrystal complexes with different supramolecular systems were successfully fabricated.Moreover,the solid-state structure of the corresponding radical macrocycle unambiguously confirmed the existence of an ordered linear array extending from the discrete mononuclear NHC-Au(Ⅰ)macrocycle via multiple noncovalent interactions.Such a radical NHC-Au(Ⅰ)macrocycle can be readily generated upon a one-electron reduction.
基金National Key Research and Development Program of China(2023YFB2905700)National Natural Science Foundation of China(62171137,62235005)Natural Science Foundation of Shanghai Municipality(24ZR1490500)。
文摘Coherent passive optical network(PON)is a promising architecture that offers high sensitivity and support for advanced modulation formats.However,fully coherent systems have high complexity and cost,making them unsuitable for cost-sensitive user-end applications.Additionally,in coherent access architectures,the lasers of optical network units(ONUs)in the upstream are typically kept on rather than being switched off to avoid wavelength drift,with the Mach–Zehnder modulators(MZMs)biased at the null point for modulation.However,the limited extinction ratio(ER)of the MZM introduces direct current(DC)leakage,which degrades system performance and limits the number of users the network can support.To address this issue,we design and fabricate the first silicon-photonics-based ultimate-simplified coherent-optics chip for ONU.The simplified transmitter employs a single MZM combined with a high-speed optical switch(OS),while the simplified receiver adopts a hybrid and a standalone photodetector(PD)for coherent detection with Alamouti coding.By integrating the OS,the upstream achieves a maximum ER of 63.93 d B,while the OS switching speed meets the guard interval requirements of PON systems.Compared to a traditional single MZM with a 26 d B ER,our design achieves an additional 37.93 d B improvement,which significantly increases the user capacity in PON systems.Comprehensive experiments were conducted to validate the proposed design.Ultimately,leveraging this ultimate-simplified coherent-optics chip,a 100 Gbps bidirectional transmission was successfully demonstrated with a power budget exceeding 29 d Bm,verifying its feasibility and cost-effectiveness for next-generation coherent optical access networks.
