Electrically variable liquid crystal lens with spiral electrode

Spiral shaped transparent electrode is used to replace the weakly conductive layer traditionally used to build an electrically tunable liquid crystal lens (TLCL) of modal control geometry. This replacement simplifies the manufacturing process and the operation control of the TLCL thanks to its lower temperature dependence. We present a theoretical analysis of its optical performance and propose an optimized structure that helps to decrease wavefront distortions. TLCLs with 2.2 mm clear apertures were fabricated and characterized in view of their use in miniature cameras. These lenses demonstrate relatively low RMS spherical aberrations (less than 0.25 um) for optical powers ranging from 0 D to 10 D. •Spiral LC lenses are simple to fabricate and less temperature dependent.•Low RMS spherical aberrations for optical powers up to +10 D.•Suitable for application in miniature cameras.•Spiral structure can be further optimized to improve the image quality.