In this communication, the fabrication of electrically tunable bifocal liquid crystal (LC) microlenses using drop‐on‐demand inkjet printing is demonstrated. By treating the glass substrate with a homeotropic alignment layer, the printed droplets are found to form plano‐convex lenses with focal lengths in the range of 220–463 µm, depending upon the number of droplets deposited at each location on the substrate. The precision of the process allows for the microlenses to be deposited in between in‐plane indium tin oxide electrodes. In the presence of a high amplitude electric field, the director within the LC droplets is observed to align with the direction of the applied field, but without any accompanying distortion in the droplet profile. However, these changes in the LC director alignment are found to result in a bifocal behavior rather than a continuous change in the focal length. It is also found that there exists a range of voltages for which two focal planes are observed.
Laser emission from a flexible defect‐mode structure consisting of two photopolymerized liquid crystal thin films separated by a dye‐doped polymethylmethacrylate defect layer is demonstrated. A simple and cost‐effective film transfer technique is used to fabricate the flexible laser and the corresponding laser emission characteristics, which shows single‐mode laser emission at λ = 582 nm, with an excitation threshold of Eth = 12.3 ± 0.5 µJ cm−2 per pulse and a slope efficiency of ηs = 6.0 ± 0.3%, are presented. The polarization state of the laser emission are also presented and are compared with the findings reported in the literature. Finally, laser‐beam steering is demonstrated up to 42° by subjecting the device to a mechanically induced deformation that creates a radius of curvature of 5 mm, which is of potential interest for conformable and wearable technology platforms.
Applications such as holography, beam steering and shaping, aberration correction, and super-resolution optical microscopy rely heavily upon technologies such as optical phase modulators. [1-5] Several technologies exist that can be used to modulate the phase of light, such as optical microelectromechanical systems (MEMS) and liquid crystal (LC)-based spatial light
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.