This study investigated direct fluorescence generation from a nematic liquid crystal(NLC)NJU-LDn-4 under femtosecond laser excitation.The absorption,transmittance,excitation,and emission spectra of the NLC were assess...This study investigated direct fluorescence generation from a nematic liquid crystal(NLC)NJU-LDn-4 under femtosecond laser excitation.The absorption,transmittance,excitation,and emission spectra of the NLC were assessed.The relationship between the femtosecond pump power and fluorescence intensity was analyzed,revealing a quadratic increase and indicating that two-photon absorption(2PA)is the primary fluorescence mechanism.The LC microstructure was designed using photoalignment technology,allowing the generated fluorescence to reflect the corresponding structure.This research can establish a foundation for tunable LC microstructured fluorescence,with potential applications in fluorescence microscopy and optoelectronics.展开更多
Controlling architecture of hierarchical microstructures in liquid crystals(LCs]plays a crucial role in the development of novel soft-matter-based devices.Chiral LC fingerprints are considered as a prospective candida...Controlling architecture of hierarchical microstructures in liquid crystals(LCs]plays a crucial role in the development of novel soft-matter-based devices.Chiral LC fingerprints are considered as a prospective candidate for various applications;however,the efficient and real-time command of fingerprint landscapes still needs to be improved.Here,we achieve elaborate rotational fingerprint superstructures via dual photopatterning semifree chiral LC films,which combine the photoalignment technique and a dynamic light patterning process.An intriguing spatial-temporal rotational behavior is presented during the patterning of chiral superstructures.This work opens new avenues for the applications of chiral LCs in soft actuators,sensing,and micromanufacturing.展开更多
A graphene-based metamaterial with tunable electromagnetically induced transparency （EIT）-like transmission is nu- merically studied in this paper. The proposed structure consists of a graphene layer composed of cou...A graphene-based metamaterial with tunable electromagnetically induced transparency （EIT）-like transmission is nu- merically studied in this paper. The proposed structure consists of a graphene layer composed of coupled cut-wire pairs printed on a substrate. The simulation confirms that an EIT-like transparency window can be observed due to indirect cou- pling in a terahertz frequency range. More importantly, the peak frequency of the transmission window can be dynamically controlled over a broad frequency range by varying the Fermi energy levels of the graphene layer through controlling the electrostatic gating. The proposed metamaterial structure offers an additional opportunity to design novel applications such as switches or modulators.展开更多
Electric fields modify the optical properties of nematic liquid crystals(NLCs) by changing the nematic molecular orientation or order parameters, which enables electro-optic applications of NLCs. However, the field-in...Electric fields modify the optical properties of nematic liquid crystals(NLCs) by changing the nematic molecular orientation or order parameters, which enables electro-optic applications of NLCs. However, the field-induced optic change is undesirable in some cases. Here, we experimentally demonstrate that polymer stabilization weakens the birefringence change of NLCs caused by the nanosecond electrically modified order parameter effect. The birefringence change is reduced by 65% in the NLC doped with 25% reactive monomer, which is polymerized close to the nematic-to-isotropic phase transition. This technique could be used in liquid crystal devices where the birefringence change is unfavored.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1405000)the Natural Science Foundation of Jiangsu Province(Nos.BK20211277 and BK20210179)+2 种基金the National Natural Science Foundation of China(NSFC)(No.62105143)the Frontier Leading Technology Basic Research Project of Jiangsu Province(No.BK20212004)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_0971)。
文摘This study investigated direct fluorescence generation from a nematic liquid crystal(NLC)NJU-LDn-4 under femtosecond laser excitation.The absorption,transmittance,excitation,and emission spectra of the NLC were assessed.The relationship between the femtosecond pump power and fluorescence intensity was analyzed,revealing a quadratic increase and indicating that two-photon absorption(2PA)is the primary fluorescence mechanism.The LC microstructure was designed using photoalignment technology,allowing the generated fluorescence to reflect the corresponding structure.This research can establish a foundation for tunable LC microstructured fluorescence,with potential applications in fluorescence microscopy and optoelectronics.
基金supported by the National Key Research and Development Program of China(Nos.2021YFA1202000 and 2022YFA1405000)the National Natural Science Foundation of China(No.52003115)+2 种基金the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212004)the Natural Science Foundation of Jiangsu Province(No.BK20200320)the support of Xiaomi Young Scholar program。
文摘Controlling architecture of hierarchical microstructures in liquid crystals(LCs]plays a crucial role in the development of novel soft-matter-based devices.Chiral LC fingerprints are considered as a prospective candidate for various applications;however,the efficient and real-time command of fingerprint landscapes still needs to be improved.Here,we achieve elaborate rotational fingerprint superstructures via dual photopatterning semifree chiral LC films,which combine the photoalignment technique and a dynamic light patterning process.An intriguing spatial-temporal rotational behavior is presented during the patterning of chiral superstructures.This work opens new avenues for the applications of chiral LCs in soft actuators,sensing,and micromanufacturing.
基金supported by the National Natural Science Foundation of China(Grant No.61307052)the Youth Funding for Science&Technology Innovation in Nanjing University of Aeronautics and Astronautics,China(Grant No.NS2014039)+3 种基金the Chinese Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20123218110017)the Innovation Program for Graduate Education of Jiangsu Province,China(Grant Nos.KYLX 0272,CXZZ13 0166,and CXLX13 155)the Open Research Program in National State Key Laboratory of Millimeter Waves of China(Grant No.K201609)the Fundamental Research Funds for the Central Universities of China(Grant No.kfjj20150407)
文摘A graphene-based metamaterial with tunable electromagnetically induced transparency （EIT）-like transmission is nu- merically studied in this paper. The proposed structure consists of a graphene layer composed of coupled cut-wire pairs printed on a substrate. The simulation confirms that an EIT-like transparency window can be observed due to indirect cou- pling in a terahertz frequency range. More importantly, the peak frequency of the transmission window can be dynamically controlled over a broad frequency range by varying the Fermi energy levels of the graphene layer through controlling the electrostatic gating. The proposed metamaterial structure offers an additional opportunity to design novel applications such as switches or modulators.
基金This work was supported by the National Natural Science Foundation of China(No.52003115)Natural Science Foundation of Jiangsu Province(Nos.BK20212004 and BK20200320)。
文摘Electric fields modify the optical properties of nematic liquid crystals(NLCs) by changing the nematic molecular orientation or order parameters, which enables electro-optic applications of NLCs. However, the field-induced optic change is undesirable in some cases. Here, we experimentally demonstrate that polymer stabilization weakens the birefringence change of NLCs caused by the nanosecond electrically modified order parameter effect. The birefringence change is reduced by 65% in the NLC doped with 25% reactive monomer, which is polymerized close to the nematic-to-isotropic phase transition. This technique could be used in liquid crystal devices where the birefringence change is unfavored.
基金The National Natural Science Foundation of China(No.61067002)Jiangxi Province Natural Science Foundation(No.2009GZW0002)Jiangxi Province Educational Committee Special Fund for Graduate Innovation(No.YC10A127)
