We show the modeling, design and fabrication for a tunable refractive lens based on liquid crystals. The lens has about 80 rings of transparent ITO conductor with an inter-ring resistor network. The width of each electrode is calculated to have maximum phase step within each electrode region about 1/8 λ. The gap between any 2 adjacent electrodes is 3 μm. The active diameter is about 4.7 mm, and our lens has a substrate gap of 10 μm, filled with a LC material of a large birefringence of Δn = 0.27. Through a via in a SiO₂ layer deposited on the ITO pattern, we run metal lines to every 10^th ring electrode for establishing the voltage profile, which is calculated by our simulation, taking into account the details of the electrode structure, the properties of the LC material used, and the desired focal length. To characterize the optical performance: we use a Mach-Zehnder interferometer to obtain the actual phase profile across the lens aperture, which fits the calculation very well in parabolic shape. An eye chart image through the lens is also taken, which shows very good resolution and contrast.

Date Published: 17 January 2011
PDF: 8 pages
Proc. SPIE 7944, Optoelectronic Interconnects and Component Integration XI, 79440S (17 January 2011); doi: 10.1117/12.876221

Published in SPIE Proceedings Vol. 7944:
Optoelectronic Interconnects and Component Integration XI
Alexei L. Glebov; Ray T. Chen, Editor(s)