Integral imaging is a promising three-dimensional (3D) imaging technique that captures and reconstructs light field information. Microlens arrays are usually used for the reconstruction process to display 3D scenes to the viewer. However, the inherent chromatic aberration of the microlens array reduces the viewing quality, and thus, broadband achromatic imaging remains a challenge for integral imaging. Here, we realize a silicon nitride metalens array in the visible region that can be used to reconstruct 3D optical scenes in the achromatic integral imaging for white light. The metalens array contains 60 × 60 polarization-insensitive metalenses with nearly diffraction-limited focusing. The nanoposts in each high-efficiency (measured as 47% on average) metalens are delicately designed with zero effective material dispersion and an effective achromatic refractive index distribution from 430 to 780 nm. In addition, such an achromatic metalens array is composed of only a single silicon nitride layer with an ultrathin thickness of 400 nm, making the array suitable for on-chip hybrid-CMOS integration and the parallel manipulation of optoelectronic information. We expect these findings to provide possibilities for full-color and aberration-free integral imaging, and we envision that the proposed approach may be potentially applicable in the fields of high-power microlithography, high-precision wavefront sensors, virtual/augmented reality and 3D imaging.

An autostereoscopic display based on two-layer lenticular lenses is proposed. The two-layer lenticular lenses include one-layer conventional lenticular lenses and additional one-layer concentrating-light lenticular lenses. Two prototypes of the proposed and conventional autostereoscopic displays are developed. At the optimum three-dimensional view distance, the luminance distribution of the prototypes along the horizontal direction is measured. By calculating the luminance distribution, the crosstalk of the prototypes is obtained. Compared with the conventional autostereoscopic display, the proposed autostereoscopic display has less crosstalk, a wider view angle, and higher efficiency of light utilization.

In this paper, a dual-view integral imaging three-dimensional (3D) display consisting of a display panel, two orthogonal polarizer arrays, a polarization switcher, and a micro-lens array is proposed. Two elemental image arrays for two different 3D images are presented by the display panel alternately, and the polarization switcher controls the polarization direction of the light rays synchronously. The two elemental image arrays are modulated by their corresponding and neighboring micro-lenses of the micro-lens array, and reconstruct two different 3D images in viewing zones 1 and 2, respectively. A prototype of the dual-view II 3D display is developed, and it has good performances.

In this paper, we propose a holographic capture and projection system of real objects based on tunable zoom lenses. Different from the traditional holographic system, a liquid lens-based zoom camera and a digital conical lens are used as key parts to reach the functions of holographic capture and projection, respectively. The zoom camera is produced by combing liquid lenses and solid lenses, which has the advantages of fast response and light weight. By electrically controlling the curvature of the liquid-liquid surface, the focal length of the zoom camera can be changed easily. As another tunable zoom lens, the digital conical lens has a large focal depth and the optical property is perfectly used in the holographic system for adaptive projection, especially for multilayer imaging. By loading the phase of the conical lens on the spatial light modulator, the reconstructed image can be projected with large depths. With the proposed system, holographic zoom capture and color reproduction of real objects can be achieved based on a simple structure. Experimental results verify the feasibility of the proposed system. The proposed system is expected to be applied to microprojection and three-dimensional display technology.

An autostereoscopic 3D projector using several 2D projectors, a projection screen, and two parallax barriers is proposed. Parallax barrier 1 facing the 2D projectors collimates the images that have aberrations on the edge of the projection screen. Parallax barrier 2 facing viewers acts as the parallax barrier in ordinary autostereoscopic 3D displays. The operation principle of the system, the calculation equations for the parallax barriers, and the capture and correction of parallax images are described in detail. A 60-inch autostereoscopic 3D projector prototype having four 2D projectors was developed. The presentation of 3D static, animation, and video images is realized by the prototype. The prototype's stereoscopic images without aberrations and with a little cross talk are sharp. Especially, its 3D resolution is the same as its 2D resolution.

Abstract— The viewing angle and flipping areas of a conventional integral‐imaging three‐dimensional (3‐D) display were analyzed. The pitches of the elemental image and micro‐lens are identical. The more micro‐lenses used, the smaller the viewing angle becomes and the wider the flipping areas become. In this paper, an improved integral‐imaging 3‐D display is presented. The pitch of the elemental image is larger than that of the micro‐lens. The single‐viewing angles of all micro‐lenses converge and there are no flipping areas at the optimal viewing distance. Computational reconstructions of improved and conventional integral imaging were carried out, and experimental results demonstrate that improved integral‐imaging 3‐D displays have a wider viewing angle than the conventional ones and do not have flipping areas at the optimal viewing distance.

In this paper, we propose a dual-view integral imaging (DVII) three-dimensional (3D) display that presents different 3D images in the left and right viewing directions simultaneously. The DVII 3D display consists of a display panel and a microlens array, and its elemental image array (EIA) is composed of two sub-EIAs. The sub-EIAs captured for two different 3D scenes are responsible for two different 3D images in the left-view and right-view integral imaging 3D displays, respectively. A prototype of the DVII 3D display using a pinhole array is developed, and good results are obtained.

We report a zoom microscope objective which can achieve continuous zoom change and correct the aberrations dynamically. The objective consists of three electrowetting liquid lenses and two glass lenses. The magnification is changed by applying voltages on the three electrowetting lenses. Besides, the three electrowetting liquid lenses can play a role to correct the aberrations. A digital microscope based on the proposed objective is demonstrated. We analyzed the properties of the proposed objective. In contrast to the conventional objectives, the proposed objective can be tuned from ~7.8 × to ~13.2 × continuously. For our objective, the working distance is fixed, which means no movement parts are needed to refocus or change its magnification. Moreover, the zoom objective can be dynamically optimized for a wide range of wavelength. Using such an objective, the fabrication tolerance of the optical system is larger than that of a conventional system, which can decrease the fabrication cost. The proposed zoom microscope objective cannot only take place of the conventional objective, but also has potential application in the 3D microscopy.