Multispectral imaging plays a crucial role in simultaneously capturing detailed spatial and spectral information,which is fundamental for understanding complex phenomena across various domains.Traditional systems face...Multispectral imaging plays a crucial role in simultaneously capturing detailed spatial and spectral information,which is fundamental for understanding complex phenomena across various domains.Traditional systems face significant challenges,such as large volume,static function,and limited wavelength selectivity.Here,we propose an innovative dynamic reflective multispectral imaging system via a thermally responsive cholesteric liquid crystal based planar lens.By employing advanced photoalignment technology,the phase distribution of a lens is imprinted to the liquid crystal director.The reflection band is reversibly tuned from 450 nm to 750 nm by thermally controlling the helical pitch of the cholesteric liquid crystal,allowing selectively capturing images in different colors.This capability increases imaging versatility,showing great potential in precision agriculture for assessing crop health,noninvasive diagnostics in healthcare,and advanced remote sensing for environmental monitoring.展开更多
Transmission beam can be modulated at the liquid-liquid interface inside an electrowetting liquid lens.The fluctuation characteristics of the interface has a decisive effect on the beam modulation.A closed cylinder in...Transmission beam can be modulated at the liquid-liquid interface inside an electrowetting liquid lens.The fluctuation characteristics of the interface has a decisive effect on the beam modulation.A closed cylinder in capillary constant scale is analyzed and the natural frequencies of a flat interface are obtained using capillary wave hydrodynamics.Results in modes 0 and 1 are in good agreement with previous experiments in the literature.The influences of the radius,the height ratio and the height-to-diameter ratio of a liquid lens on the interface eigenfrequencies are analyzed.展开更多
A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display（LCFLD） with a holographic screen was demonstrated.The proposed display system has high efficiency,simpl...A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display（LCFLD） with a holographic screen was demonstrated.The proposed display system has high efficiency,simple fabrication,and low manufacturing cost due to the absence of a polarizer and color filter.展开更多
Optical axial scanning is essential process to obtain 3D information of biological specimens. To realize optical axial scanning without moving, the tunable lens is a solution. However, the conventional tunable lenses ...Optical axial scanning is essential process to obtain 3D information of biological specimens. To realize optical axial scanning without moving, the tunable lens is a solution. However, the conventional tunable lenses usually induce non-uniform magnification and resolution issues. In this paper, we report a movable electrowetting optofluidic lens. Unlike the conventional tunable lens, our proposed optofluidic lens has two liquid-liquid (L-L) interfaces, which can move in the cell by an external voltage. The object distance and image distance are adjusted by shifting the L-L interface position. Therefore, the proposed lens can realize optical axial scanning with uniform magnification and resolution in microscopy. To prove the concept, we fabricate an optofluidic lens and use it in optical axial scanning. The scanning distance is more than 1 mm with uniform magnification and good imaging quality. Widespread application of such a new adaptive zoom lens is foreseeable.展开更多
Liquid lens offers a novel approach to achieving large depth of field,wide viewing angle,high speed,and high-quality imaging in zoom optical systems.However,the aperture and reliability limit the lens’s performance i...Liquid lens offers a novel approach to achieving large depth of field,wide viewing angle,high speed,and high-quality imaging in zoom optical systems.However,the aperture and reliability limit the lens’s performance in various optical applications.The liquid material is crucial for the reliability of the large-aperture liquid lens.To solve the dielectric failure problem associated with the large aperture,we first reveal the mechanism of dielectric failure based on the transport properties of electrolyte solutions and the impact of electrochemical reaction rates from physical chemistry so as to propose a theoretical method to suppress dielectric failure fundamentally.Based on this theory,we develop a series of non-aqueous organic solutions to suppress high-voltage dielectric failure.Next,we identify the optimal formulation for comprehensive optical performance and fabricate a centimeter-level large-aperture electrowetting liquid lens.This lens features an optical power variation range of−11.98m^(−1) to 12.93m^(−1),with clear and high-quality imaging function,which can enlarge the field of view and depth adjustment range of holographic reconstructions while maintaining excellent edge clarity of the reconstructed images.The proposed centimeter-level large-aperture non-aqueous electrowetting liquid lens effectively suppresses dielectric failure under high voltage,demonstrates excellent optical performance,and holds exciting potential for applications in 3D display,precision measurement,biomedical observation,and more.展开更多
For the narrowband of liner charge-coupled device （CCD） receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can con...For the narrowband of liner charge-coupled device （CCD） receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can concentrate on a strip facula, Considered the effective CCD length and selection of lens parameters, the system can be optimized. Correspondingly to the CCD pixels, the ray is composed of much angle information. By widening the parallel ray or increasing the lens aperture, luminous flux can be ensured when oblique incidence. Meanwhile, the effective working range can also be improved. Based on the experimental data, cylindrical system could be applied in accurate angle measurement. It has been proved feasible that the cylindrical system can be used in anchor behavior study for liquid crystal （LC） case. The low-power He-Ne laser cylindrical system can carry out the previous effect in high power laser spherical system.展开更多
In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the fe...In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the features of the practical realization of ultrasonic imaging systems based on phased arrays and offers an alternative solution of imaging on the basis of the acoustic lenses of refractive and diffraction types. Using lenses eliminates many of the technical and technological problems associated with the development of multi-element phased arrays. It is shown that lens systems allow using traditional methods of transformation of acoustic fields into the visible images by 2D piezo matrix and a more promising way of acoustooptical transformation based on coherent optical interferometry.展开更多
This paper describes how the maximum blur radius affects the depth results by depth from the defocus(DFD)method based on liquid crystal(LC)lens.Boundary frequency is determined by the maximum blur radius.It is found t...This paper describes how the maximum blur radius affects the depth results by depth from the defocus(DFD)method based on liquid crystal(LC)lens.Boundary frequency is determined by the maximum blur radius.It is found that if the maximum blur radius used in the calculation is larger than the real value,the depth resolution obtained is reduced;on the other hand,if one smaller than the real value is used,the depth resolution in the middle range of the scene is increased,but errors occur in the near and far planes.Using the maximum blur radius close to the real one results in the best depth results.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1203700)the National Natural Science Foundation of China(NSFC)(Nos.62405129 and 62035008)+1 种基金the University Research Project of Guangzhou Education Bureau(No.202235053)the Natural Science Foundation of Jiangsu Province(No.BK20241197).
文摘Multispectral imaging plays a crucial role in simultaneously capturing detailed spatial and spectral information,which is fundamental for understanding complex phenomena across various domains.Traditional systems face significant challenges,such as large volume,static function,and limited wavelength selectivity.Here,we propose an innovative dynamic reflective multispectral imaging system via a thermally responsive cholesteric liquid crystal based planar lens.By employing advanced photoalignment technology,the phase distribution of a lens is imprinted to the liquid crystal director.The reflection band is reversibly tuned from 450 nm to 750 nm by thermally controlling the helical pitch of the cholesteric liquid crystal,allowing selectively capturing images in different colors.This capability increases imaging versatility,showing great potential in precision agriculture for assessing crop health,noninvasive diagnostics in healthcare,and advanced remote sensing for environmental monitoring.
文摘Transmission beam can be modulated at the liquid-liquid interface inside an electrowetting liquid lens.The fluctuation characteristics of the interface has a decisive effect on the beam modulation.A closed cylinder in capillary constant scale is analyzed and the natural frequencies of a flat interface are obtained using capillary wave hydrodynamics.Results in modes 0 and 1 are in good agreement with previous experiments in the literature.The influences of the radius,the height ratio and the height-to-diameter ratio of a liquid lens on the interface eigenfrequencies are analyzed.
基金Project supported by Partner State Key Laboratory on Advanced Displays and Optoelectronics Technologies HKUST,Chinathe National Natural Science Foundation of China(Grant Nos.61435008 and 61575063)the Fundamental Research Funds for the Central Universities,China(Grant No.WM1514036)
文摘A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display（LCFLD） with a holographic screen was demonstrated.The proposed display system has high efficiency,simple fabrication,and low manufacturing cost due to the absence of a polarizer and color filter.
文摘Optical axial scanning is essential process to obtain 3D information of biological specimens. To realize optical axial scanning without moving, the tunable lens is a solution. However, the conventional tunable lenses usually induce non-uniform magnification and resolution issues. In this paper, we report a movable electrowetting optofluidic lens. Unlike the conventional tunable lens, our proposed optofluidic lens has two liquid-liquid (L-L) interfaces, which can move in the cell by an external voltage. The object distance and image distance are adjusted by shifting the L-L interface position. Therefore, the proposed lens can realize optical axial scanning with uniform magnification and resolution in microscopy. To prove the concept, we fabricate an optofluidic lens and use it in optical axial scanning. The scanning distance is more than 1 mm with uniform magnification and good imaging quality. Widespread application of such a new adaptive zoom lens is foreseeable.
基金supported by the National Natural Science Foundation of China under Grant No.U23A20368,62175006,and 62275009.
文摘Liquid lens offers a novel approach to achieving large depth of field,wide viewing angle,high speed,and high-quality imaging in zoom optical systems.However,the aperture and reliability limit the lens’s performance in various optical applications.The liquid material is crucial for the reliability of the large-aperture liquid lens.To solve the dielectric failure problem associated with the large aperture,we first reveal the mechanism of dielectric failure based on the transport properties of electrolyte solutions and the impact of electrochemical reaction rates from physical chemistry so as to propose a theoretical method to suppress dielectric failure fundamentally.Based on this theory,we develop a series of non-aqueous organic solutions to suppress high-voltage dielectric failure.Next,we identify the optimal formulation for comprehensive optical performance and fabricate a centimeter-level large-aperture electrowetting liquid lens.This lens features an optical power variation range of−11.98m^(−1) to 12.93m^(−1),with clear and high-quality imaging function,which can enlarge the field of view and depth adjustment range of holographic reconstructions while maintaining excellent edge clarity of the reconstructed images.The proposed centimeter-level large-aperture non-aqueous electrowetting liquid lens effectively suppresses dielectric failure under high voltage,demonstrates excellent optical performance,and holds exciting potential for applications in 3D display,precision measurement,biomedical observation,and more.
基金This project is supported by Natural Science and Research Foundation ofTsinghua University, China (No.JC2002039).
文摘For the narrowband of liner charge-coupled device （CCD） receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can concentrate on a strip facula, Considered the effective CCD length and selection of lens parameters, the system can be optimized. Correspondingly to the CCD pixels, the ray is composed of much angle information. By widening the parallel ray or increasing the lens aperture, luminous flux can be ensured when oblique incidence. Meanwhile, the effective working range can also be improved. Based on the experimental data, cylindrical system could be applied in accurate angle measurement. It has been proved feasible that the cylindrical system can be used in anchor behavior study for liquid crystal （LC） case. The low-power He-Ne laser cylindrical system can carry out the previous effect in high power laser spherical system.
文摘In nuclear reactors cooled by liquid metals, ultrasound is the only type of field that allows obtaining images of the reactor cores and diagnostics of the integrity of the fuel assemblies. The article discusses the features of the practical realization of ultrasonic imaging systems based on phased arrays and offers an alternative solution of imaging on the basis of the acoustic lenses of refractive and diffraction types. Using lenses eliminates many of the technical and technological problems associated with the development of multi-element phased arrays. It is shown that lens systems allow using traditional methods of transformation of acoustic fields into the visible images by 2D piezo matrix and a more promising way of acoustooptical transformation based on coherent optical interferometry.
基金This work was partially supported by Sichuan Science and Technology Program(Grant No.20YYJC4365).
文摘This paper describes how the maximum blur radius affects the depth results by depth from the defocus(DFD)method based on liquid crystal(LC)lens.Boundary frequency is determined by the maximum blur radius.It is found that if the maximum blur radius used in the calculation is larger than the real value,the depth resolution obtained is reduced;on the other hand,if one smaller than the real value is used,the depth resolution in the middle range of the scene is increased,but errors occur in the near and far planes.Using the maximum blur radius close to the real one results in the best depth results.
