Ommatidia structure based on double layers of liquid crystal microlens array.

We present a new liquid crystal (LC) microlens structure having ommatidia function, which consists of the overlapped patterned electrode layers. Each electrode layer has a circular electrode array with a different size. Two electrode layers are deposited on the surface of a glass substrate and insulated by thin SiO₂ coating, which act as controlling electrodes. A plane electrode layer deposited on the surface of another glass substrate acts as the base electrode. Two glass substrates are made into a LC cell filled with nematic LC material. When a voltage signal is applied to the controlling electrode and base electrode, each circular unit of the array can focus along the optical axis and has good focusing character, and it behaves as a common microconvex lens. The whole circular array achieves ommatidia optical characters because of many microconvex lenses imaging to the objects simultaneously. Two circular arrays can both image to the objects and have different fields of view, which have extraordinary ommatidia effects. The common optical properties of the LC microlens are also demonstrated experimentally.