Fabrication and characterization of large aperture adaptive modal liquid crystal lens with a PEDOT:PSS/PVA/DMSO blend used as the modal and rubbing layer

An adaptive modal liquid crystal lens (AMLCL) with a 5 mm aperture and thickness of 20 µm was fabricated and studied. PEDOT:PSS/PVA/DMSO polymer blend film was used as both the modal and rubbing layers simultaneously. Using the modal layer as the rubbing layer facilitates and simplifies cell preparation. An optimal concentration of polymer blend, the 0.1-µm-thick modal layer had a 5 MΩ/□ sheet resistance. AMLCL electrodes were broken down into four parts and the cell placed in the optical setup to study the wavefront shape. It was shown that by applying the trigger voltage to different parts of the electrode and removing parts of the circuit, the cell could function as a spherical, cylindrical, or prismatic lens. Further, the electric power consumption was studied at different voltages and frequencies, showing that the spherical lens requires 0.5 mW to reach its maximum optical power at 1 kHz. Shack-Hartmann wavefront sensor was used to study the AMLCL’s aberrations. Tip aberration in this cell is attributed to the pretilt of the Liquid Crystal (LC) molecules at the surfaces that deflect the transmitting light from its straight path. It was shown that higher-order aberrations are negligible compared to the spherical aberration, which is reduced by raising the frequency to 1 kHz.