In this paper, a continuous optical zoom microscopy imaging system based on liquid lenses is proposed. Compared with traditional microscopes, which have discrete magnification, requiring manual conversion of the objective lens to change the magnification, the proposed microscope can continuously change the magnification of the targets in real-time. An adaptive zoom microscope, a liquid lens driving board, a microscope bracket, an adjustable three-dimensional stage and a light source are stacked to form the main framework of the continuous optical zoom microscopy imaging system. The adaptive zoom microscope which is composed of four electrowetting liquid lenses and six glass lenses form the main imaging element of the microscope. By changing the driving voltage which is applied to the four liquid lenses, the focal length of the liquid lenses can be modulated to achieve continuous zooming. By contrast, in traditional microscopes, the zooming process can only be achieved by rotating the eyepieces at different magnifications. At a fixed working distance, the magnification of the proposed microscope can change continuously from ∼9.6× to ∼22.2× with a response time of ∼50ms. Moreover, an axial depth scanning of ∼1000µm can be achieved without any mechanical movement. Our experiments proved that the microscope has stable performance and high consistency during zooming. Therefore, the proposed microscope has obvious advantages over the traditional microscopes in observing dynamic samples with different magnifications and can be commercialized for further expanding the applications in biochemical and pathological analysis.

Due to the limitations of spatial bandwidth product and data transmission bandwidth, the field of view, resolution, and imaging speed constrain each other in an optical imaging system. Here, a fast-zoom and high-resolution sparse compound-eye camera (CEC) based on dual-end collaborative optimization is proposed, which provides a cost-effective way to break through the trade-off among the field of view, resolution, and imaging speed. In the optical end, a sparse CEC based on liquid lenses is designed, which can realize large-field-of-view imaging in real time, and fast zooming within 5 ms. In the computational end, a disturbed degradation model driven super-resolution network (DDMDSR-Net) is proposed to deal with complex image degradation issues in actual imaging situations, achieving high-robustness and high-fidelity resolution enhancement. Based on the proposed dual-end collaborative optimization framework, the angular resolution of the CEC can be enhanced from 71.6" to 26.0", which provides a solution to realize high-resolution imaging for array camera dispensing with high optical hardware complexity and data transmission bandwidth. Experiments verify the advantages of the CEC based on dual-end collaborative optimization in high-fidelity reconstruction of real scene images, kilometer-level long-distance detection, and dynamic imaging and precise recognition of targets of interest.

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 −11.98 m⁻¹ to 12.93 m⁻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.

We propose a multi-view 2D/3D switchable display by using cylindrical liquid crystal (LC) lens array with a low operating voltage and fast response time. The cylindrical LC lens array is composed of three parts: the LC layer, a top-plane indium tin oxide (ITO) electrode, and bottom periodic strip ITO electrodes. In the voltage-off state, the cylindrical LC lens array is equivalent to a transparent glass substrate and the viewers can see a clear 2D image. In the 3D mode, the cylindrical LC lens array can be used as a cylindrical lens array under a suitable operating voltage. As a result, the 2D and 3D images can be switched according to the state of the cylindrical LC lens array. The experimental result shows that the 2D/3D switchable display with the cylindrical LC lens array has a wider viewing angle, has no moiré pattern, and is much thinner compared to the other 2D/3D switchable display devices.

A liquid lens, especially an electrowetting liquid lens, is filled with two immiscible liquids based on the electrowetting on dielectric effect. The chamber structure of the liquid lens is generally cylindrical or conical, and the filling liquids generally contain water. In this paper, a non-aqueous organic solution based large-aperture spherical electrowetting liquid lens (SELL) with a wide tunable focal length range is proposed. The spherical chamber can enlarge the contact angle range and the focal length range compared with the conventional cylindrical electrowetting liquid lens. The SELL has a low threshold voltage, high breakdown voltage, fast response time, and large zoom ratio with excellent image quality. Experimental results show that the non-aqueous organic liquids can avoid the generation of bubbles resulting from the hydrolysis phenomenon and still keep the lens working even when the dielectric layer fails. Furthermore, the imaging experiment shows that the focal length range can be tuned under different volume ratios of a conductive liquid to insulating liquid. The SELL can be applied in microscopes, cameras, telescopes, etc.

The field-of-view (FOV), depth of field, and resolution of conventional microscopes are constrained by each other; therefore, a zoom function is required. Traditional zoom methods lose real-time performance and have limited information throughput, severely limiting their application, especially in three-dimensional dynamic imaging and large-amount or large-size sample scanning. Here, an adaptive multiscale (AMS) imaging mechanism combining the benefits of liquid lenses and multiscale imaging techniques is proposed to realize the functions of fast zooming, wide working distance (WD) range and large FOV on a self-developed AMS microscope. The design principles were revealed. Moreover, a nonuniform-distortion-correction algorithm and a composite patching algorithm were designed to improve image quality. The continuous tunable magnification range of the AMS microscope is from 9× to 18×, with the corresponding FOV diameters and resolution ranging from 2.31 to 0.98 mm and from 161 to 287 line-pairs/mm, respectively. The extended WD range is 0.8 mm and the zoom response time is 38 ms. Experiments demonstrated the advantages of the proposed microscope in pathological sample scanning, thick-sample imaging, microfluidic process monitoring, and the observation of living microorganisms. The proposed microscope is the first step towards zoom multiscale imaging technology and is expected to be applied in life sciences, medical diagnosis, and industrial detection. The field-of-view (FOV), depth of field, and resolution of conventional microscopes are constrained by each other; therefore, a zoom function is required. Traditional zoom methods lose real-time performance and have limited information throughput, severely limiting their application, especially in three-dimensional dynamic imaging and large-amount or large-size sample scanning. Here, an adaptive multiscale (AMS) imaging mechanism combining the benefits of liquid lenses and multiscale imaging techniques is proposed to realize the functions of fast zooming, wide working distance (WD) range and large FOV on a self-developed AMS microscope. The design principles were revealed. Moreover, a nonuniform-distortion-correction algorithm and a composite patching algorithm were designed to improve image quality. The continuous tunable magnification range of the AMS microscope is from 9× to 18×, with the corresponding FOV diameters and resolution ranging from 2.31 to 0.98 mm and from 161 to 287 line-pairs/mm, respectively. The extended WD range is 0.8 mm and the zoom response time is 38 ms. Experiments demonstrated the advantages of the proposed microscope in pathological sample scanning, thick-sample imaging, microfluidic process monitoring, and the observation of living microorganisms. The proposed microscope is the first step towards zoom multiscale imaging technology and is expected to be applied in life sciences, medical diagnosis, and industrial detection.