Abstract

Information processing and communications using light as carrier often requires besides a set of static optical elements a number of devices which offer the capability of changing dynamically their optical properties thus enabling active control of the light wavefront. A very attractive candidate to achieve such performance is the homogeneous nematic liquid crystal (HNLC), being able to modulate only the wavefront with small electrical signals while keeping the transmission efficiency high (see for example).^1–3 R. Matic⁴ introduced the idea of using electrodes of different resistivities to control the wavefront with a linear phase gradient profile. Discussions about detailed experimental studies, however, especially with respect to the spatial modulation characteristics of the LC cell actually used, were missing. In this paper, we report an experimental demonstration of the spatially distributed phase modulation taking place in LC panels with electrodes of distributed resistivity and introduce a number of novel optical functions.

© 1995 IEEE