Background Augmen ted reality(AR)smartglasses are considered as the next generation of smart devices to replace mobile phones,and are widely concerned.But at present,AR smartglasses are usually designed according to t...Background Augmen ted reality(AR)smartglasses are considered as the next generation of smart devices to replace mobile phones,and are widely concerned.But at present,AR smartglasses are usually designed according to the human normal eyes.In order to experience AR smartglasses perfectly,abnormal eye users must first wear diopters.Methods For people with astigmatism to use AR smartglasses without wearing a diopter lens,a cylindrical lens waveguide grating is designed in this study based on the principle of holographic waveguide grating.First,a cylindrical lens waveguide substrate is constructed for external light deflection to satisfy the users'normal viewing of the real world.Further,a variable period grating structure is established based on the cylindrical lens waveguide substrate to normally emit the light from the virtual world in the optical machine to the human eyes.Finally,the structural parameters of grating are optimized to improve the diffraction efficiency.Results The results show that the structure of cylindrical lens waveguide grating allows people with astigmatism to wear AR smartglasses directly.The total light utilization rate reaches 90%with excellent imaging uniformity.The brightness difference is less than 0.92%and the vertical field of view is 10°.Conclusions This research serves as a guide for AR product designs for people with long/short sightedness and promotes the development of such products.展开更多
The growth of entire functions under the q-difference operators is studied inthis paper, and then some properties of Julia set of entire functions under the higher orderq-difference operators are obtained.
Hollow-core fiber(HCF)is a special optical waveguide type that can guide light in the air or liquid core surrounded by properly designed cladding structures.The guiding modes of the fiber can generate sufficient optic...Hollow-core fiber(HCF)is a special optical waveguide type that can guide light in the air or liquid core surrounded by properly designed cladding structures.The guiding modes of the fiber can generate sufficient optical gradient forces to balance the gravity of the particles or confine the atom clouds,forming a stable optical trap in the hollow core.The levitated objects can be propelled over the fiber length along the beam axis through an imbalance of the optical scattering forces or by forming an optical lattice by the counter-propagating beams.The ability to overcome the diffraction of the laser beam in HCF can significantly increase the range of the optical manipulation compared with standard free-space optical tweezers,opening up vast ranges of applications that require long-distance optical control.Since the first demonstration of optical trapping in HCF,hollow-core-fiber-based optical trap(HCF-OT)has become an essential branch of optical tweezer that draws intense research interests.Fast progress on the fundamental principle and applied aspects of HCF-OT has been visible over the past two decades.In recent years,significant milestones in reducing the propagation loss of HCF have been achieved,making HCF an attractive topic in the field of optics and photonics.This further promotes the research and applications of HCF-OT.This review starts from the mechanism of light guidance of HCF,mainly focusing on the issues related to the optical trap in the hollow core.The basic principles and key features of HCF-OT,from optical levitation to manipulation and the detection of macroscopic particles and atoms,are summarized in detail.The key applications of HCF-OT,the challenges and future directions of the technique are also discussed.展开更多
文摘Background Augmen ted reality(AR)smartglasses are considered as the next generation of smart devices to replace mobile phones,and are widely concerned.But at present,AR smartglasses are usually designed according to the human normal eyes.In order to experience AR smartglasses perfectly,abnormal eye users must first wear diopters.Methods For people with astigmatism to use AR smartglasses without wearing a diopter lens,a cylindrical lens waveguide grating is designed in this study based on the principle of holographic waveguide grating.First,a cylindrical lens waveguide substrate is constructed for external light deflection to satisfy the users'normal viewing of the real world.Further,a variable period grating structure is established based on the cylindrical lens waveguide substrate to normally emit the light from the virtual world in the optical machine to the human eyes.Finally,the structural parameters of grating are optimized to improve the diffraction efficiency.Results The results show that the structure of cylindrical lens waveguide grating allows people with astigmatism to wear AR smartglasses directly.The total light utilization rate reaches 90%with excellent imaging uniformity.The brightness difference is less than 0.92%and the vertical field of view is 10°.Conclusions This research serves as a guide for AR product designs for people with long/short sightedness and promotes the development of such products.
基金supported by the National Natural Science Foundation of China(11571049,11101048)
文摘The growth of entire functions under the q-difference operators is studied inthis paper, and then some properties of Julia set of entire functions under the higher orderq-difference operators are obtained.
基金supported by the National Key Research and Development Program of China(2023YFC3010001)National Natural Science Foundation of China(62275021,62450075,W2412086,62175044,12404315)+1 种基金Beijing Natural Science Foundation(4232078)Science and Technology Innovation Program of Beijing Institute of Technology Teli Students’Science and Technology Innovation Team Project(2024CX06101).
文摘Hollow-core fiber(HCF)is a special optical waveguide type that can guide light in the air or liquid core surrounded by properly designed cladding structures.The guiding modes of the fiber can generate sufficient optical gradient forces to balance the gravity of the particles or confine the atom clouds,forming a stable optical trap in the hollow core.The levitated objects can be propelled over the fiber length along the beam axis through an imbalance of the optical scattering forces or by forming an optical lattice by the counter-propagating beams.The ability to overcome the diffraction of the laser beam in HCF can significantly increase the range of the optical manipulation compared with standard free-space optical tweezers,opening up vast ranges of applications that require long-distance optical control.Since the first demonstration of optical trapping in HCF,hollow-core-fiber-based optical trap(HCF-OT)has become an essential branch of optical tweezer that draws intense research interests.Fast progress on the fundamental principle and applied aspects of HCF-OT has been visible over the past two decades.In recent years,significant milestones in reducing the propagation loss of HCF have been achieved,making HCF an attractive topic in the field of optics and photonics.This further promotes the research and applications of HCF-OT.This review starts from the mechanism of light guidance of HCF,mainly focusing on the issues related to the optical trap in the hollow core.The basic principles and key features of HCF-OT,from optical levitation to manipulation and the detection of macroscopic particles and atoms,are summarized in detail.The key applications of HCF-OT,the challenges and future directions of the technique are also discussed.
