Improvement of aberration properties of liquid crystal microlenses using the stacked electrode structure

Optical properties of liquid crystal (LC) microlenses using a stacked electrode structure are studied, experimentally and theoretically. Detailed electric potential distribution properties and liquid crystal molecular orientations are investigated using computer simulations in order to discuss a relationship between interference fringe patterns and applied voltages of four electrode layers. An optimum condition so that the interference fringe patterns become symmetric is clearly derived from the simulation results. Spherical aberration and astigmatism properties are also discussed, and they are compensated by adjusting the thickness of the LC layer and using an elliptically hole-patterned electrode. This work leads to the development of LC microlenses with large NA values and small aberrations.