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Iterative freeform lens design for prescribed irradiance on curved target

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Opto-Electronic Advances 2020年第7期3卷 1-9,I0001页

作者： Zexin Feng dewen cheng Yongtian Wang Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing100081China Beijing Key Laboratory of Advanced Optical Remote Sensing Technology School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China

Current freeform illumination optical designs are mostly focused on producing prescribed irradiance distributions on planar ***,we aim to design freeform optics that could generate a desired illumination on a curved target from a point source,which is still a *** reduce the difficulties that arise from the curved target by involving its varying z-coordinates in the iterative wavefront tailoring(IWT)*** new IWT-based method is developed under the stereographic coordinate system with a special mesh transformation of the source domain,which is suitable for light sources with light emissions in semi space such as LED *** first example demonstrates that a rectangular flat-top illumination can be generated on an undulating surface by a spherical-freeform lens for a Lambertian *** second example shows that our method is also applicable for producing a non-uniform irradiance distribution in a circular region of the undulating surface.

关键词： freeform optics prescribed irradiance distribution curved target iterative wavefront tailoring

Retinal projection head-mounted display

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Frontiers of Optoelectronics 2017年第1期10卷 1-8页

作者： Junguo LIN dewen cheng cheng YAO Yongtian WANG Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optoelectronics Beijing Institute of Technology Beijing 100081 China

Retinal projection displays （RPDs） are an important development direction for head-mounted dis- plays （HMDs）. This paper reviews the literature on optical engineering aspects based on the data on advanced technology in RPD design and development. The review includes the principles and applications of four theories, e. g., the Maxwellian view and its modified modality and the monocular and binocular depth cues of stereoscopic objects in the physiology of the human visual system. To support the Maxwellian view and achieve retinal projec- tion systems with depth cues, results of previous design works were summarized using different methods and their advantages and disadvantages are analyzed. With an extremely long focal depth, a prototype of a full-color stereoscopic see-through RPD system was discussed. Finally, a brief outlook of the future development trends and applications of the RPDs was presented

关键词： retinal projection display (RPD) Maxwellian view depth cues stereoscopic see-through

FreeformNet:fast and automatic generation of multiple-solution freeform imaging systems enabled by deep learning

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Photonics Research 2023年第8期11卷 1408-1422页

作者： BOYU MAO TONG YANG HUIMING XU WENCHEN CHEN dewen cheng YONGTIAN WANG Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Advanced Optical Remote Sensing Technology School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China

Using freeform optical surfaces in lens design can lead to much higher system specifications and performance while significantly reducing volume and ***,because of the complexity of freeform surfaces,freeform optical design using traditional methods requires extensive human effort and sufficient design experience,while other design methods have limitations in design efficiency,simplicity,and *** learning can solve these issues by summarizing design knowledge and applying it to design tasks with different system and structure *** propose a deep-learning framework for designing freeform imaging *** generate the data set automatically using a combined sequential and random system evolution *** combine supervised learning and unsupervised learning to train the network so that it has good generalization ability for a wide range of system and structure parameter *** generated network FreeformNet enables fast generation(less than 0.003 s per system)of multiple-solution systems after we input the design requirements,including the system and structure *** can filter and sort solutions based on a given criterion and use them as good starting points for quick final optimization(several seconds for systems with small or moderate field-of-view in general).The proposed framework presents a revolutionary approach to the lens design of freeform or generalized imaging systems,thus significantly reducing the time and effort expended on optical design.

关键词： network simplicity starting

Full degree-of-freedom polarization hologram by freeform exposure and inkjet printing

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PhotoniX 2023年第1期4卷 48-63页

作者： Jianghao Xiong Haizheng Zhong dewen cheng Shin-Tson Wu Yongtian Wang Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijingChina College of Optics and Photonics University of Central FloridaOrlandoFL 32816USA MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices School of Materials Science&EngineeringBeijing Institute of TechnologyBeijingChina

Since the invention of holography by Dennis Gabor,the fabrication of holograms has mainly relied on direct recording of wavefront by engraving the intensity fringes of interfering electric fields into the holographic *** degree-of-freedom(DoF)is often limited,especially for its usage as a holographic optical element in imaging or display systems,as what is recorded is what to *** this work,based on the emerging self-assembled photo-aligned liquid crystal,a polarization hologram with full DoF for local manipulation of optical structure is *** ability to record an arbitrary wavefront(in-plane DoF)is achieved by freeform surface exposure,while the local adjustment of deposited liquid crystal(out-of-plane DoF)is realized by inkjet *** methodology for designing and fabricating such a hologram is exemplified by building a full-color retinal scanning display without color ***,the arbitrary wavefront modulation capability helps to eliminate the aberrations caused by mismatched exposure and display *** local liquid crystal adjustment ability enables the suppression of crosstalk by variation of chiral pitch and film thickness to tune the peak and valley of Bragg diffraction *** demonstrated method is expected to greatly impact the fields of advanced imaging and display,such as augmented reality and virtual reality,that require optics with an ultrathin form factor and high degrees of design freedom simultaneously.

关键词： holographic arbitrary eliminate

Design and manufacture AR head-mounted displays:A review and outlook

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Light(Advanced Manufacturing) 2021年第3期2卷 114-133页

作者： dewen cheng Qiwei Wang Yue Liu Hailong Chen Dongwei Ni Ximeng Wang cheng Yao Qichao Hou Weihong Hou Gang Luo Yongtian Wang Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China Beijing NED+AR Ltd Beijing 100081China Obducat Technologies AB Scheelevägen 2SE-22363 LundSweden

Augmented reality head-mounted displays(AR-HMDs)enable users to see real images of the outside world and visualize virtual information generated by a computer at any time and from any location,making them useful for various *** manufacture of AR-HMDs combines the fields of optical engineering,optical materials,optical coating,precision manufacturing,electronic science,computer science,physiology,ergonomics,*** paper primarily focuses on the optical engineering of *** combiners and display devices are used to combine real-world and virtual-world objects that are visible to the human *** this review,existing AR-HMD optical solutions employed for optical combiners are divided into three categories:optical solutions based on macro-,micro-,and *** physical principles,optical structure,performance parameters,and manufacturing process of different types of AR-HMD optical solutions are subsequently ***,their advantages and disadvantages are investigated and *** addition,the bottlenecks and future development trends in the case of AR-HMD optical solutions are discussed.

关键词： mounted combine outside

Optical design of a compact and high-transmittance compressive sensing imaging system enabled by freeform optics

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Chinese Optics Letters 2021年第11期19卷 117-123页

作者： dewen cheng Hailong Chen Tong Yang Jun Ke Yang Li Yongtian Wang School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Advanced Optical Remote Sensing Technology School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China

Using compressive sensing for imaging has many applications, and it is an important branch of computational *** this Letter, freeform surfaces are introduced in the hardware optical system design of a compressive sensing imager. The system works under the medium wave infrared band and realizes a 16× compression with a field-of-view of 7.5°× 6°. Good imaging performance is achieved in both the entire system and the freeform objective optics. Compared with the system using all spherical lenses, the volume of the freeform system is about 1/3 smaller, and the total transmittance is about 56%higher, which shows the benefits of using freeform surfaces for compressive sensing and computational imaging.

关键词： compressive sensing freeform optics compactness and high-transmittance joint optimization

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头盔显示器发展综述

计算机辅助设计与图形学学报 2016年第6期28卷 896-904页

作者：高源刘越程德文王涌天北京理工大学光电学院北京100081

随着虚拟现实与增强现实技术的快速发展,近年来越来越多的虚拟现实与增强现实相关应用走入大众视野.在众多显示设备中,头盔显示器以其高沉浸感、实时交互性及其广阔的应用领域在虚拟现实与增强现实技术中占据重要地位.文中介绍了头盔显... 详细信息

随着虚拟现实与增强现实技术的快速发展,近年来越来越多的虚拟现实与增强现实相关应用走入大众视野.在众多显示设备中,头盔显示器以其高沉浸感、实时交互性及其广阔的应用领域在虚拟现实与增强现实技术中占据重要地位.文中介绍了头盔显示器光学系统成像原理;分析总结了从不同的技术角度解决的传统头盔显示器体积与质量大、调焦与辐辏不匹配等问题的3种新型头盔显示器,包括自由曲面头盔显示器、波导型头盔显示器和真实立体感头盔显示器,阐述了用户佩戴头盔显示器的视疲劳主观和客观评测方法;最后对头盔显示器的未来发展趋势进行了展望.

关键词：虚拟现实与增强现实头盔显示器视疲劳评测方法

Freeform OST-HMD system with large exit pupil diameter and vision correction capability

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Photonics Research 2022年第1期10卷 21-32页

作者： dewen cheng JIAXI DUAN HAILONG CHEN HE WANG DANYANG LI QIWEI WANG QICHAO HOU TONG YANG WEIHONG HOU DONGHUA WANG XIAOYU CHI BIN JIANG YONGTIAN WANG Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China Ned Co. Ltd.Beijing 100081China Goertek Co. Ltd.Weifang 261031China

Compactness and light weight,large exit pupil diameter and distance,small distortion for virtual image,and see-through light paths are pivotal factors to achieve a better,wearable experience of optical see-through headmounted displays(OST-HMDs).In addition,light efficiency of the virtual image light path is an important factor for heat dissipation in HMD *** paper presents a new type of OST-HMD optical system that includes three wedge-shaped freeform prisms and two symmetric *** on a 0.71 ***,an OST-HMD prototype with a diagonal field of view(FOV)of 45.3°,an F-number(F/#)of 1.8,an exit pupil size of 12 mm×8 mm,and an eye relief of 18 mm is *** maximum value of distortion of the final system is 0.6%and 0.4%for virtual image and see-through light path,*** overall dimension of the optical system per eye is no larger than 30 mm(width)×40 mm(height)×14 mm(thickness),and the weight of the optical module including lenses,holder,and microdisplay is 12.8 *** light efficiency of the virtual image light path is up to 50%higher than those of other OST-HMD optical solutions.

关键词： system distortion correction

实现给定能量比离散光斑阵列的自由曲面分束器

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光学学报 2020年第17期40卷 176-184页

作者：司佳冯泽心程德文王涌天北京理工大学光电学院北京市混合现实与新型显示工程技术研究中心北京100081

采用自由曲面透镜作为分束器以生成具有任意能量比的离散光斑阵列。根据能量守恒定律,将入射光束划分为一系列与光斑阵列对应的子区域。对于每个子区域,采用分离变量法计算子区域与相应光斑之间的光线映射关系,并采用最小二乘法构造遵... 详细信息

采用自由曲面透镜作为分束器以生成具有任意能量比的离散光斑阵列。根据能量守恒定律,将入射光束划分为一系列与光斑阵列对应的子区域。对于每个子区域,采用分离变量法计算子区域与相应光斑之间的光线映射关系,并采用最小二乘法构造遵循该映射关系的自由曲面。提供两个设计实例以检验自由曲面分束器的可行性:第一个设计可生成具有相同能量比例的高斯光斑阵列,第二个设计可产生具有预设不均匀能量比例的矩形平顶光斑阵列。仿真结果表明,考虑菲涅耳损耗后,两个设计实例的光输出比均高于89%。

关键词：光学设计分束器自由曲面光学非成像光学