High-aperture piezo-driven liquid tunable lens with real-time feedback control

Piezo-driven tunable lenses offer high-aperture, compact size, and fast response, but hysteresis and creep in their piezoelectric actuators limit precision and complicate real-time control. We demonstrate a real-time feedback controller that leverages the direct piezoelectric effect to linearize the system response, enabling efficient linear control algorithms. Running on an FPGA, it delivers a 0.88 ms settling time and <0.5<i>%</i> RMS tracking error, demonstrating high fidelity, bandwidth, and linearity. Finite element simulations guide the integrated sensor design, validated through full opto-electro-mechanical characterization of the lens and controller.