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We have fabricated a fully-flexible, focus-tunable microlens array on a sheet and demonstrated its imaging capabilities. Each liquid lens of the array is individually tunable via electrowetting on dielectric (EWOD) actuation and is situated on a polydimethylsiloxane (PDMS) substrate, which allows the lens array to operate as a reconfigurable optical system. In particular, we observed a significant increase in the field of view (FOV) of the system to 40.4° by wrapping it on a cylindrical surface as compared to the FOV of 21.5° obtained by the array on a planer surface. We also characterized the liquid lenses of the system, observing a range of focus length from 20.2 mm to 9.2 mm as increased voltage was applied to each EWOD lens. A Shack–Hartmann wavefront sensor (SHWS) was used to measure the wavefront of the lens as it was actuated, and the aberrations of the lens were assessed by reporting the Zernike coefficients of the wavefronts.

Optically trapped laser-cooled polar molecules hold promise for new science and technology in quantum information and quantum simulation. Large numerical aperture optical access and long trap lifetimes are needed for many studies, but these requirements are challenging to achieve in a magneto-optical trap (MOT) vacuum chamber that is connected to a cryogenic buffer gas beam source, as is the case for all molecule laser cooling experiments so far. Long distance transport of molecules greatly eases fulfilling these requirements as molecules are placed into a region separate from the MOT chamber. We realize a fast transport method for ultracold molecules based on an electronically focus-tunable lens combined with an optical lattice. The high transport speed is achieved by the 1D red-detuned optical lattice, which is generated by interference of a focus-tunable laser beam and a focus-fixed laser beam. Efficiency of 48(8)% is realized in the transport of ultracold calcium monofluoride (CaF) molecules over 46 cm distance in 50 ms, with a moderate heating from 32(2)  μ K to 53(4)  μ K. Positional stability of the molecular cloud allows for stable loading of an optical tweezer array with single molecules.

Imaging systems that exploit arrays of photodetectors in curvilinear layouts are attractive due to their ability to match the strongly nonplanar image surfaces (i.e., Petzval surfaces) that form with simple lenses, thereby creating new design options. Recent work has yielded significant progress in the realization of such \"eyeball\" cameras, including examples of fully functional silicon devices capable of collecting realistic images. Although these systems provide advantages compared to those with conventional, planar designs, their fixed detector curvature renders them incompatible with changes in the Petzval surface that accompany variable zoom achieved with simple lenses. This paper describes a class of digital imaging device that overcomes this limitation, through the use of photodetector arrays on thin elastomeric membranes, capable of reversible deformation into hemispherical shapes with radii of curvature that can be adjusted dynamically, via hydraulics. Combining this type of detector with a similarly tunable, fluidic plano-convex lens yields a hemispherical camera with variable zoom and excellent imaging characteristics. Systematic experimental and theoretical studies of the mechanics and optics reveal all underlying principles of operation. This type of technology could be useful for night-vision surveillance, endoscopic imaging, and other areas that require compact cameras with simple zoom optics and wide-angle fields of view.

We have designed, assembled, and evaluated a compact instrument capable of capturing the wavefront phase in real time, across various scenarios. Our approach simplifies the optical setup and configuration, which reduces the conventional capture and computation time when compared to other methods that use two defocused images. We evaluated the feasibility of using an electrically tunable lens in our camera by addressing its issues and optimizing its performance. Additionally, we conducted a comparison study between our approach and a Shack–Hartmann sensor. The camera was tested on multiple targets, such as deformable mirrors, lenses with aberrations, and a liquid lens in movement. Working at the highest resolution of the CMOS sensor with a small effective pixel size enables us to achieve the maximum level of detail in lateral resolution, leading to increased sensitivity to high-spatial-frequency signals.

We demonstrate a remote axial scanning system for optical scanning microscopy that operates in the millisecond range over a large depth of approximately 80 times the longitudinal size of the focal spot, and that retains the focal spot size by compensating for spherical aberrations. This is achieved by controlling the divergence of the scanning beam with a special pair of adjacent diffractive optical elements (DOEs) that form a so-called moiré lens whose focal length is controlled by a relative rotation between the two DOEs. The moiré lens system is used in reflection mode, where one of the DOEs is fixed while the second, reflecting DOE is mounted perpendicularly on the axis of a rotating Galvo stage that can achieve an angular range of ± 20 ∘ in the 50 Hz range. The moiré lens is specially adapted to allow a large optical power change of ±13 dpt in this angular range while compensating for the spherical aberrations, which otherwise would be induced by the focus shift. The remote focusing module can be used in conjunction with any laser scanning microscopy method, such as confocal or multi-photon microscopy. We experimentally demonstrate its operation in a fast confocal profilometer.

This work demonstrates the detections and mappings of a solid object using a thermally tunable solid-state phononic crystal lens at low frequency for potential use in future long-distance detection. The phononic crystal lens is infiltrated with a polyvinyl alcohol-based poly n-isopropyl acrylamide (PVA-PNIPAm) bulk hydrogel polymer. The hydrogel undergoes a volumetric phase transition due to a temperature change leading to a temperature-dependent sound velocity and density. The temperature variation from 20 °C to 39 °C changes the focal length of the tunable solid-state lens by 1 cm in the axial direction. This thermo-reversible tunable focal length lens was used in a monostatic setup for one- and two-dimensional mapping scans in both frequency domain echo-intensity and temporal domain time-of-flight modes. The experimental results illustrated 1.03 ± 0.15λ and 2.35 ± 0.28λ on the lateral and axial minimum detectable object size. The experiments using the tunable lens demonstrate the capability to detect objects by changing the temperature in water without translating an object, source, or detector. The time-of-flight mode modality using the tunable solid-state phononic lens increases the signal-to-noise ratio compared to a conventional phononic crystal lens.

In this investigation, we propose a motionless polarizing structured illumination microscopy as an axially sectioning and reflective-type device to measure the 3D surface profiles of specimens. Based on the spatial phase-shifting technique to obtain the visibility of the illumination pattern. Instead of using a grid, a Wollaston prism is used to generate the light pattern by the stable interference of two beams. As the polarization states of two beams are orthogonal with each other, a polarization pixelated CMOS camera can simultaneously obtain four phase-shifted patterns with the beams after passing through a quarter wave plate based on the spatial phase-shifting technique with polarization. In addition, a focus tunable lens is used to eliminate a mechanical moving part for the axial scanning of the specimen. In the experimental result, a step height sample and a concave mirror were measured with 0.05 µm and 0.2 mm repeatabilities of step height and the radius of curvature, respectively.

We present an optical setup with focus-tunable lenses to dynamically control the waist and focus position of a laser beam, in which we transport a trapped ultracold cloud of 87Rb over a distance of . The scheme allows us to shift the focus position at constant waist, providing uniform trapping conditions over the full transport length. The fraction of atoms that are transported over the entire distance comes near to unity, while the heating of the cloud is in the range of a few microkelvin. We characterize the position stability of the focus and show that residual drift rates in focus position can be compensated for by counteracting with the tunable lenses. Beyond being a compact and robust scheme to transport ultracold atoms, the reported control of laser beams makes dynamic tailoring of trapping potentials possible. As an example, we steer the size of the atomic cloud by changing the waist size of the dipole beam.

Compact and entirely soft optics with tunable and adaptive properties drive the development of life‐like soft robotic systems. Yet, existing approaches are either slow, require rigid components, or use high operating voltages of several kilovolts. Here, soft focus‐tunable lenses are introduced, which operate at practical voltages, cover a high range of adjustable focal lengths, and feature response times in the milliseconds range. The nature‐inspired design comprises a liquid‐filled elastomeric lens membrane, which is inflated by zipping electroactive polymers to tune the focal length. An analytic description of the tunable lens supports optimized designs and accurate prediction of the lens characteristics. Focal length changes between 22 and 550 mm (numerical aperture 0.14–0.005) within 260 ms, equal in performance to human eyes, are demonstrated for a lens with 3 mm aperture radius, while applying voltages below 500 V. The presented model, design rules, and fabrication methods address central challenges of soft electrostatic actuators and optical systems, and pave the way toward autonomous bio‐inspired robots and machines. Zipping electroactive polymer (ZEAP) actuators drive bioinspired tunable lenses with large focal length changes, are low‐cost, and fast. They achieve actuation speeds and focal length changes comparable to the human eye, switching the focus from 550 to 22 mm within 260 ms. Being overall soft, ZEAP tunable lenses advance bio‐mimetic vision systems and actuators.

The application of focus-tunable lenses (FTL) has significantly expanded in the field of photonics in the last decade, establishing these devices as fundamental optoelectronic components in most experimental setups. An electrically-addressed FTL allows fine, continuous, and dynamic power adjustment within a range of diopters. In many applications, the FTL is oriented horizontally, with vertical optical axis. However, those applications requiring alternative orientations are prone to be affected by aberrations due to the gravitational force effects on the optical fluid and elastic membrane of this device. A new FTL introduces a compensation for gravity, aiming to compensate for the induced coma. This study focuses on the optical performance of a gravity-compensated FTL, Optotune EL-16-40-GTC-VIS-5D (Optotune Switzerland AG). A comprehensive experimental wavefront characterization was conducted across the addressable power range (5 D) by measuring and analyzing the induced primary astigmatism, coma and spherical aberrations in a 6 mm-diameter aperture, with 530 nm illumination, with the lens in both horizontal (i.e., parallel to laboratory ground) and vertical (upright) lens orientations. A detailed comparison with two uncompensated standard models of the same brand (Optotune EL-16-40-TC-VIS-5D and EL-16-40-TC-VIS-5D-E) is presented in terms of measured wavefront error. The results showed the gravity-compensated FTL effectively corrected induced vertical coma when used upright. In contrast, the astigmatism induced (0.06 μ m in both horizontal and vertical orientations) exceeded the observed vertical coma (around 0.030 μ m) of the upright standard models. Additionally, such astigmatism (0.06 μ m) is approximately three times greater than the astigmatism induced by the standard models in both positions. These results provide a valuable insight about induced aberrations, which can be particularly relevant for vision testing experiments and adaptive optics applications, both requiring precise aberration control. The astigmatism introduced by gravity-compensated FTLs, as well as other induced aberrations, can be significant, potentially masking the effects of other optical components or acting as confounding factors.