An analytic equation interpreting the intensity of ultrasound-modulated scattering light is derived, based on diffusion theory and previous explanations of the intensity modulation mechanism. Furthermore, an experimen...An analytic equation interpreting the intensity of ultrasound-modulated scattering light is derived, based on diffusion theory and previous explanations of the intensity modulation mechanism. Furthermore, an experiment of ultrasonic modulation of incoherent light in a scattering medium is developed. This analytical model agrees well with experimental results,which confirms the validity of the proposed intensity modulation mechanism. The model supplements the existing research on the ultrasonic modulation mechanism of scattering light.展开更多
The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound...The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound pressure spectrum model is presented to describe its non-cavitation noise with application of generalized acoustic analogy method, the modulation mechanism is expressed with the improvement of sound pressure model. The power spectrum and modulation spectrum are presented by numerical simulation. Theoretical analysis and nu- merical simulation results are verified by the cavitation tunnel experiment. The modulation model of counter-rotation propeller is beneficial to the prediction modulation characteristics and identification of underwater high-speed vehicles.展开更多
Current you only look once(YOLO)-based algorithm model is facing the challenge of overwhelming parameters and calculation complexity under the printed circuit board(PCB)defect detection application scenario.In order t...Current you only look once(YOLO)-based algorithm model is facing the challenge of overwhelming parameters and calculation complexity under the printed circuit board(PCB)defect detection application scenario.In order to solve this problem,we propose a new method,which combined the lightweight network mobile vision transformer(Mobile Vi T)with the convolutional block attention module(CBAM)mechanism and the new regression loss function.This method needed less computation resources,making it more suitable for embedded edge detection devices.Meanwhile,the new loss function improved the positioning accuracy of the bounding box and enhanced the robustness of the model.In addition,experiments on public datasets demonstrate that the improved model achieves an average accuracy of 87.9%across six typical defect detection tasks,while reducing computational costs by nearly 90%.It significantly reduces the model's computational requirements while maintaining accuracy,ensuring reliable performance for edge deployment.展开更多
An improved adaptive particle swarm optimization(IAPSO)algorithm is presented for solving the minimum makespan problem of job shop scheduling problem(JSP).Inspired by hormone modulation mechanism,an adaptive hormonal ...An improved adaptive particle swarm optimization(IAPSO)algorithm is presented for solving the minimum makespan problem of job shop scheduling problem(JSP).Inspired by hormone modulation mechanism,an adaptive hormonal factor(HF),composed of an adaptive local hormonal factor(H l)and an adaptive global hormonal factor(H g),is devised to strengthen the information connection between particles.Using HF,each particle of the swarm can adjust its position self-adaptively to avoid premature phenomena and reach better solution.The computational results validate the effectiveness and stability of the proposed IAPSO,which can not only find optimal or close-to-optimal solutions but also obtain both better and more stability results than the existing particle swarm optimization(PSO)algorithms.展开更多
Laser powder bed fusion(LPBF)combined with reaction bonding(RB)of Al particles is an effective method for preparing high-performance 3D Al_(2)O_(3) ceramic foams.However,the indistinct microstructure evolution hinders...Laser powder bed fusion(LPBF)combined with reaction bonding(RB)of Al particles is an effective method for preparing high-performance 3D Al_(2)O_(3) ceramic foams.However,the indistinct microstructure evolution hinders the regulation of pore features and the improvement of synthetic properties.Herein,the microstructure evolution of the Al_(2)O_(3) ceramic foams during the LPBF/RB process is clarified by various characterization methods,and the corresponding mechanical property modulation is realized by optimizing LPBF parameters,organic binder(E12 epoxy resin)content,heating rate,sintering time,and coral-like Al_(2)O_(3) content.The expansion from Al_(2)O_(3) outward growth and Al granule precipitation counteracts the shrinkage from E12 decomposition and Al_(2)O_(3) sintering,resulting in an ultra-low shrinkage of 0.94%–3.01%.The pore structures of particle packing pores,hollow spheres,and microporous structures allow a tunable porosity of 52.6%–73.7%.The in-situ formation of multi-scale features including hollow spheres,flaky grains,whiskers,nanofibers,and bond bridges brings about a remarkably high bending strength of 6.5–38.3 MPa.Ourfindings reveal the relationship between microstructure evolution and property optimization of high-performance ceramic foams,with potential significance for microstructure design and practical application.展开更多
The heart rate variability signal is highly correlated with the respiration even at high workload exercise.It is also known that this phenomenon still exists during increasing exercise.In the current study,we managed ...The heart rate variability signal is highly correlated with the respiration even at high workload exercise.It is also known that this phenomenon still exists during increasing exercise.In the current study,we managed to model this correlation during increasing exercise using the time varying integral pulse frequency modulation(TVIPFM)model that relates the mechanical modulation(MM)to the respiration and the cardiac rhythm.This modulation of the autonomic nervous system(ANS)is able to simultaneously decrease sympathetic and increase parasympathetic activity.The TVIPFM model takes into consideration the effect of the increasing exercise test,where the effect of a time-varying threshold on the heart period is studied.Our motivation is to analyze the heart rate variability(HRV)acquired by time varying integral pulse frequency modulation using time frequency representations.The estimated autonomic nervous system(ANS)modulating signal is filtered throughout the respiration using a time varying filtering,during exercise stress testing.And after summing power of the filtered signal,we compare the power of the filtered modulation of the ANS obtained with different time frequency representations:smoothed pseudo Wigner–Ville representation,spectrogram and their reassignments.After that,we used a student t-test p<0.01 to compare the power of heart rate variability in the frequency band of respiration and elsewhere.展开更多
In this work, we propose a high-fidelity phonon-mediated entangling gate in a hybrid mechanical system based on two silicon-vacancy color centers in diamond. In order to suppress the influence of the spin decoherence ...In this work, we propose a high-fidelity phonon-mediated entangling gate in a hybrid mechanical system based on two silicon-vacancy color centers in diamond. In order to suppress the influence of the spin decoherence on the entangling gate, we use a continuous dynamical decoupling approach to create new dressed spin states, which are less sensitive to environmental fluctuations and exhibit an extended T_(2)^(*) spin dephasing time. The effective spin-spin Hamiltonian modified by the mechanical driving field and the corresponding master equation are derived in the dispersive regime. We show that in the presence of the mechanical driving field, the effective spin-spin coupling can be highly controlled. By calculating the entangling gate fidelity in the dressed basis, we find that once the mechanical field is turned on, the gate fidelity can be significantly improved. In particular, under an optimized spin-phonon detuning and a stronger Rabi frequency of the mechanical driving field, the two-qubit gate is capable of reaching fidelity exceeding 0.99. Moreover, by employing appropriate driving modulation, we show that a highfidelity full quantum gate can be also realized, in which the initial and final spin states are on a bare basis. Our work provides a promising scheme for realizing high-fidelity quantum information processing.展开更多
DNA hydrogels are three-dimensional polymer networks constructed using DNA as the structural building block.Due to the tight binding between hydrophilic groups on DNA chains and water molecules,they exhibit outstandin...DNA hydrogels are three-dimensional polymer networks constructed using DNA as the structural building block.Due to the tight binding between hydrophilic groups on DNA chains and water molecules,they exhibit outstanding plasticity and fluid thermodynamic properties,making them one of the best choices for mimicking natural biological tissues.By controlling the backbone building blocks,gelation conditions,and cross-linking methods of DNA hydrogels,hydrogels with different mechanical strengths can be obtained,thus expanding their applications in the field of biology.This review first introduces the relationship between the mechanical properties of DNA hydrogels and their structure,elucidates the approaches and strategies for mechanical property modulation,and focuses on the scheme of controllable design to modulate the mechanical properties of DNA hydrogels for applications in biosensing,cellular function regulation,and bone tissue engineering.Furthermore,this review outlines the future development directions and challenges faced in the mechanical property modulation of DNA hydrogels,providing useful information for the precise design of DNA hydrogels for biological research.展开更多
Flexible hybrid systems usually combine soft modules(mechanically matched with skin or clothes)and hard modulus(like rigid circuits).However,the risk of interface failure due to modulus mismatch between flexible compo...Flexible hybrid systems usually combine soft modules(mechanically matched with skin or clothes)and hard modulus(like rigid circuits).However,the risk of interface failure due to modulus mismatch between flexible components and rigid circuits limits the system’s complexity and durability.The diverse features of flexible components further complicate the development of a universal interface.In this work,we demonstrated a cocoon-mimetic feature-matched interface(CFI)that offers stable electrical contact with flexible surface.It also matches flexible systems features in stretchability(lower than 0.22Ωcm^(-1)during 900%elongation),durability(stable resistance after 20000 times 100%elongation),breathability(gas permeability 614 mm S^(-1))and self-adhesive(0.18±0.01 N mm^(-1)).We developed a direct spray-on-skin sensor and used CFI to form a hand task recognition system.This system,deployable in seconds,has 97.7%accuracy in recognition of eight hand tasks.This research offers a promising solution for flexible hybrid systems interfacing challenges.展开更多
With the rapid advancement of virtual reality,dynamic gesture recognition technology has become an indispensable and critical technique for users to achieve human–computer interaction in virtual environments.The reco...With the rapid advancement of virtual reality,dynamic gesture recognition technology has become an indispensable and critical technique for users to achieve human–computer interaction in virtual environments.The recognition of dynamic gestures is a challenging task due to the high degree of freedom and the influence of individual differences and the change of gesture space.To solve the problem of low recognition accuracy of existing networks,an improved dynamic gesture recognition algorithm based on ResNeXt architecture is proposed.The algorithm employs three-dimensional convolution techniques to effectively capture the spatiotemporal features intrinsic to dynamic gestures.Additionally,to enhance the model’s focus and improve its accuracy in identifying dynamic gestures,a lightweight convolutional attention mechanism is introduced.This mechanism not only augments the model’s precision but also facilitates faster convergence during the training phase.In order to further optimize the performance of the model,a deep attention submodule is added to the convolutional attention mechanism module to strengthen the network’s capability in temporal feature extraction.Empirical evaluations on EgoGesture and NvGesture datasets show that the accuracy of the proposed model in dynamic gesture recognition reaches 95.03%and 86.21%,respectively.When operating in RGB mode,the accuracy reached 93.49%and 80.22%,respectively.These results underscore the effectiveness of the proposed algorithm in recognizing dynamic gestures with high accuracy,showcasing its potential for applications in advanced human–computer interaction systems.展开更多
The rise of the engine remanufacturing industry has resulted in increased possibilities of energy conservation during the remanufacturing process,and scheduling could exert significant effects on the energy performanc...The rise of the engine remanufacturing industry has resulted in increased possibilities of energy conservation during the remanufacturing process,and scheduling could exert significant effects on the energy performance of manufacturing systems.However,only a few studies have specifically addressed energy-efficient scheduling for remanufacturing.Considering the uncertain processing time and routes and the operation characteristics of remanufacturing,we used the crankshaft as an illustrative case and built a fuzzy job-shop scheduling model to minimize the energy consumption during remanufacturing.An improved adaptive genetic algorithm was developed by using the hormone modulation mechanism to deal with the scheduling problem that simultaneously involves parallel machines,batch machines,and uncertain processing routes and time.The algorithm demonstrated superior performance in terms of optimal value,run time,and convergent generation in comparison with other algorithms.Computational results indicated that the optimal scheduling scheme is expected to generate 1.7 kW∙h of energy saving for the investigated problem size.In addition,the scheme could improve the energy efficiency of the crankshaft remanufacturing process by approximately 5%.This study provides a basis for production managers to improve the sustainability of remanufacturing through energy-aware scheduling.展开更多
By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modula...By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modulating the thickness of the air cavity, we demonstrate that a single resonant peak can shift from 416.1 to 667.3 nm in the band gap at normal incidence by means of the transfer matrix method. The research also shows that the transmittance of the channel can be maximized when the number of periodic Li F/Ga Sb layers on one side of the air defect layer is equal to that of the other side. When adding a period to both sides respectively, the full width at half maximum of the defect mode is reduced by one order of magnitude. This structure will provide a promising approach to fabricate practical tunable filters in the visible region with ultra-wide tuning range.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61178089)the Key Program of Science and Technology of Fujian Province,China(Grant No.2011Y0019)the Educational Department of Fujian Province,China(Grant No.JA13074)
文摘An analytic equation interpreting the intensity of ultrasound-modulated scattering light is derived, based on diffusion theory and previous explanations of the intensity modulation mechanism. Furthermore, an experiment of ultrasonic modulation of incoherent light in a scattering medium is developed. This analytical model agrees well with experimental results,which confirms the validity of the proposed intensity modulation mechanism. The model supplements the existing research on the ultrasonic modulation mechanism of scattering light.
基金supported by the National Natural Science Foundation of China(11704345)the Key Laboratory of Science and Technology for National Defence Foundation(9140C290304140C29133)
文摘The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound pressure spectrum model is presented to describe its non-cavitation noise with application of generalized acoustic analogy method, the modulation mechanism is expressed with the improvement of sound pressure model. The power spectrum and modulation spectrum are presented by numerical simulation. Theoretical analysis and nu- merical simulation results are verified by the cavitation tunnel experiment. The modulation model of counter-rotation propeller is beneficial to the prediction modulation characteristics and identification of underwater high-speed vehicles.
基金supported by the National Natural Science Foundation of China(Nos.62373215,62373219 and 62073193)the Natural Science Foundation of Shandong Province(No.ZR2023MF100)+1 种基金the Key Projects of the Ministry of Industry and Information Technology(No.TC220H057-2022)the Independently Developed Instrument Funds of Shandong University(No.zy20240201)。
文摘Current you only look once(YOLO)-based algorithm model is facing the challenge of overwhelming parameters and calculation complexity under the printed circuit board(PCB)defect detection application scenario.In order to solve this problem,we propose a new method,which combined the lightweight network mobile vision transformer(Mobile Vi T)with the convolutional block attention module(CBAM)mechanism and the new regression loss function.This method needed less computation resources,making it more suitable for embedded edge detection devices.Meanwhile,the new loss function improved the positioning accuracy of the bounding box and enhanced the robustness of the model.In addition,experiments on public datasets demonstrate that the improved model achieves an average accuracy of 87.9%across six typical defect detection tasks,while reducing computational costs by nearly 90%.It significantly reduces the model's computational requirements while maintaining accuracy,ensuring reliable performance for edge deployment.
基金Supported by the National Natural Science Foundation of China(51175262)the Research Fund for Doctoral Program of Higher Education of China(20093218110020)+2 种基金the Jiangsu Province Science Foundation for Excellent Youths(BK201210111)the Jiangsu Province Industry-Academy-Research Grant(BY201220116)the Innovative and Excellent Foundation for Doctoral Dissertation of Nanjing University of Aeronautics and Astronautics(BCXJ10-09)
文摘An improved adaptive particle swarm optimization(IAPSO)algorithm is presented for solving the minimum makespan problem of job shop scheduling problem(JSP).Inspired by hormone modulation mechanism,an adaptive hormonal factor(HF),composed of an adaptive local hormonal factor(H l)and an adaptive global hormonal factor(H g),is devised to strengthen the information connection between particles.Using HF,each particle of the swarm can adjust its position self-adaptively to avoid premature phenomena and reach better solution.The computational results validate the effectiveness and stability of the proposed IAPSO,which can not only find optimal or close-to-optimal solutions but also obtain both better and more stability results than the existing particle swarm optimization(PSO)algorithms.
文摘Laser powder bed fusion(LPBF)combined with reaction bonding(RB)of Al particles is an effective method for preparing high-performance 3D Al_(2)O_(3) ceramic foams.However,the indistinct microstructure evolution hinders the regulation of pore features and the improvement of synthetic properties.Herein,the microstructure evolution of the Al_(2)O_(3) ceramic foams during the LPBF/RB process is clarified by various characterization methods,and the corresponding mechanical property modulation is realized by optimizing LPBF parameters,organic binder(E12 epoxy resin)content,heating rate,sintering time,and coral-like Al_(2)O_(3) content.The expansion from Al_(2)O_(3) outward growth and Al granule precipitation counteracts the shrinkage from E12 decomposition and Al_(2)O_(3) sintering,resulting in an ultra-low shrinkage of 0.94%–3.01%.The pore structures of particle packing pores,hollow spheres,and microporous structures allow a tunable porosity of 52.6%–73.7%.The in-situ formation of multi-scale features including hollow spheres,flaky grains,whiskers,nanofibers,and bond bridges brings about a remarkably high bending strength of 6.5–38.3 MPa.Ourfindings reveal the relationship between microstructure evolution and property optimization of high-performance ceramic foams,with potential significance for microstructure design and practical application.
基金This work was supported by College of Engineering and Technology,the American University of the Middle East,Kuwait.Homepage:https://www.aum.edu.kw.
文摘The heart rate variability signal is highly correlated with the respiration even at high workload exercise.It is also known that this phenomenon still exists during increasing exercise.In the current study,we managed to model this correlation during increasing exercise using the time varying integral pulse frequency modulation(TVIPFM)model that relates the mechanical modulation(MM)to the respiration and the cardiac rhythm.This modulation of the autonomic nervous system(ANS)is able to simultaneously decrease sympathetic and increase parasympathetic activity.The TVIPFM model takes into consideration the effect of the increasing exercise test,where the effect of a time-varying threshold on the heart period is studied.Our motivation is to analyze the heart rate variability(HRV)acquired by time varying integral pulse frequency modulation using time frequency representations.The estimated autonomic nervous system(ANS)modulating signal is filtered throughout the respiration using a time varying filtering,during exercise stress testing.And after summing power of the filtered signal,we compare the power of the filtered modulation of the ANS obtained with different time frequency representations:smoothed pseudo Wigner–Ville representation,spectrogram and their reassignments.After that,we used a student t-test p<0.01 to compare the power of heart rate variability in the frequency band of respiration and elsewhere.
基金supported by the Natural Science Foundation of Henan Province (No. 222300420233)。
文摘In this work, we propose a high-fidelity phonon-mediated entangling gate in a hybrid mechanical system based on two silicon-vacancy color centers in diamond. In order to suppress the influence of the spin decoherence on the entangling gate, we use a continuous dynamical decoupling approach to create new dressed spin states, which are less sensitive to environmental fluctuations and exhibit an extended T_(2)^(*) spin dephasing time. The effective spin-spin Hamiltonian modified by the mechanical driving field and the corresponding master equation are derived in the dispersive regime. We show that in the presence of the mechanical driving field, the effective spin-spin coupling can be highly controlled. By calculating the entangling gate fidelity in the dressed basis, we find that once the mechanical field is turned on, the gate fidelity can be significantly improved. In particular, under an optimized spin-phonon detuning and a stronger Rabi frequency of the mechanical driving field, the two-qubit gate is capable of reaching fidelity exceeding 0.99. Moreover, by employing appropriate driving modulation, we show that a highfidelity full quantum gate can be also realized, in which the initial and final spin states are on a bare basis. Our work provides a promising scheme for realizing high-fidelity quantum information processing.
基金supported by the National Key Research and Development Program of China(2023YFB3208204)the National Natural Science Foundation of China(12305400,12105352)+2 种基金the Natural Science Foundation of Shanghai,China(22ZR1470600)the Natural Science Foundation of Shandong Province(ZR2019MB068,ZR2022MB012,ZR2021QE167)the Xiangfu Lab Research Project(XF012022E0100).
文摘DNA hydrogels are three-dimensional polymer networks constructed using DNA as the structural building block.Due to the tight binding between hydrophilic groups on DNA chains and water molecules,they exhibit outstanding plasticity and fluid thermodynamic properties,making them one of the best choices for mimicking natural biological tissues.By controlling the backbone building blocks,gelation conditions,and cross-linking methods of DNA hydrogels,hydrogels with different mechanical strengths can be obtained,thus expanding their applications in the field of biology.This review first introduces the relationship between the mechanical properties of DNA hydrogels and their structure,elucidates the approaches and strategies for mechanical property modulation,and focuses on the scheme of controllable design to modulate the mechanical properties of DNA hydrogels for applications in biosensing,cellular function regulation,and bone tissue engineering.Furthermore,this review outlines the future development directions and challenges faced in the mechanical property modulation of DNA hydrogels,providing useful information for the precise design of DNA hydrogels for biological research.
基金supported by the National Key Research and Development Program of China(2021YFC3002200)the National Natural Science Foundation of China(U20A20168)+1 种基金the Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(CI2023C002YG,ZN2023A01)a grant from the Guoqiang Institute,Tsinghua University.
文摘Flexible hybrid systems usually combine soft modules(mechanically matched with skin or clothes)and hard modulus(like rigid circuits).However,the risk of interface failure due to modulus mismatch between flexible components and rigid circuits limits the system’s complexity and durability.The diverse features of flexible components further complicate the development of a universal interface.In this work,we demonstrated a cocoon-mimetic feature-matched interface(CFI)that offers stable electrical contact with flexible surface.It also matches flexible systems features in stretchability(lower than 0.22Ωcm^(-1)during 900%elongation),durability(stable resistance after 20000 times 100%elongation),breathability(gas permeability 614 mm S^(-1))and self-adhesive(0.18±0.01 N mm^(-1)).We developed a direct spray-on-skin sensor and used CFI to form a hand task recognition system.This system,deployable in seconds,has 97.7%accuracy in recognition of eight hand tasks.This research offers a promising solution for flexible hybrid systems interfacing challenges.
文摘With the rapid advancement of virtual reality,dynamic gesture recognition technology has become an indispensable and critical technique for users to achieve human–computer interaction in virtual environments.The recognition of dynamic gestures is a challenging task due to the high degree of freedom and the influence of individual differences and the change of gesture space.To solve the problem of low recognition accuracy of existing networks,an improved dynamic gesture recognition algorithm based on ResNeXt architecture is proposed.The algorithm employs three-dimensional convolution techniques to effectively capture the spatiotemporal features intrinsic to dynamic gestures.Additionally,to enhance the model’s focus and improve its accuracy in identifying dynamic gestures,a lightweight convolutional attention mechanism is introduced.This mechanism not only augments the model’s precision but also facilitates faster convergence during the training phase.In order to further optimize the performance of the model,a deep attention submodule is added to the convolutional attention mechanism module to strengthen the network’s capability in temporal feature extraction.Empirical evaluations on EgoGesture and NvGesture datasets show that the accuracy of the proposed model in dynamic gesture recognition reaches 95.03%and 86.21%,respectively.When operating in RGB mode,the accuracy reached 93.49%and 80.22%,respectively.These results underscore the effectiveness of the proposed algorithm in recognizing dynamic gestures with high accuracy,showcasing its potential for applications in advanced human–computer interaction systems.
基金The authors highly appreciate the investigation opportunities provided by SINOTRUK,Jinan Fuqiang Power Co.,Ltd.We are also grateful for the financial support from the National Natural Science Foundation of China(Grant Nos.51775086 and 51605169)Natural Science Foundation of Guangdong Province China(Grant No.2014A030310345).
文摘The rise of the engine remanufacturing industry has resulted in increased possibilities of energy conservation during the remanufacturing process,and scheduling could exert significant effects on the energy performance of manufacturing systems.However,only a few studies have specifically addressed energy-efficient scheduling for remanufacturing.Considering the uncertain processing time and routes and the operation characteristics of remanufacturing,we used the crankshaft as an illustrative case and built a fuzzy job-shop scheduling model to minimize the energy consumption during remanufacturing.An improved adaptive genetic algorithm was developed by using the hormone modulation mechanism to deal with the scheduling problem that simultaneously involves parallel machines,batch machines,and uncertain processing routes and time.The algorithm demonstrated superior performance in terms of optimal value,run time,and convergent generation in comparison with other algorithms.Computational results indicated that the optimal scheduling scheme is expected to generate 1.7 kW∙h of energy saving for the investigated problem size.In addition,the scheme could improve the energy efficiency of the crankshaft remanufacturing process by approximately 5%.This study provides a basis for production managers to improve the sustainability of remanufacturing through energy-aware scheduling.
基金Project supported by the National Natural Science Foundation of China(Nos.61575138,61307069,51205273)the Top Young Academic Leaders and the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi
文摘By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modulating the thickness of the air cavity, we demonstrate that a single resonant peak can shift from 416.1 to 667.3 nm in the band gap at normal incidence by means of the transfer matrix method. The research also shows that the transmittance of the channel can be maximized when the number of periodic Li F/Ga Sb layers on one side of the air defect layer is equal to that of the other side. When adding a period to both sides respectively, the full width at half maximum of the defect mode is reduced by one order of magnitude. This structure will provide a promising approach to fabricate practical tunable filters in the visible region with ultra-wide tuning range.
