Frequency-stable liquid crystal lenses using a circumferentially segmented concentric electrode

A circumferentially segmented concentric electrode is proposed for a large-aperture liquid crystal (LC) lens to address the issue of phase deviation from the parabolic profile caused by alternating current (AC) driving voltages. This design offers a simple and effective method for realizing large-aperture LC lenses that maintain a stable parabolic phase profile across a wider frequency range. An equivalent circuit model of the LC lens is established, and analysis shows that increasing the number of electrode segments brings the voltage distribution closer to a parabolic profile. In the experiments, LC lenses with a 5 mm aperture and a 30 µm LC layer were prepared using both unsegmented and eight-segmented electrodes. The results demonstrate that the segmented electrode design notably enhances frequency stability, with the lens maintaining a nearly ideal parabolic phase profile over a frequency range of up to 8 kHz.