Asymmetrical dual tapered fiber Mach-Zehnder interferometer for fiber-optic directional tilt sensor.

This work proposes a novel, highly sensitive and directional fiber tilt sensor that is based on an asymmetrical dual tapered fiber Mach-Zehnder interferometer (ADTFMZI). The fiber-optic tilt sensor consists of two abrupt tapers with different tapered waists into which are incorporated a set of iron spheres to generate an asymmetrical strain in the ADTFMZI that is correlated with the tilt angle and the direction of inclination. Owing to the asymmetrical structure of the dual tapers, the proposed sensor can detect the non-horizontal/horizontal state of a structure and whether the test structure is tilted to clockwise or counterclockwise by measuring the spectral responses.

Error sources and their impact on the performance of dual-wedge beam steering systems.

This paper presents analytical and numerical results that elucidate the impact of error sources on the performance of dual-wedge beam steering systems. Different types of error sources are considered. Specifically, we investigate optical distortions in the pattern scanned out by a single ray through a pair of rotatable wedge elements with slightly different parameters.

Electrically switchable liquid crystal Fresnel lens using UV-modified alignment film.

A simple method to make a switchable liquid crystal (LC) Fresnel lens with high diffraction efficiency and a low driving voltage was proposed based on the photo-induced surface modification of the vertical alignment layer. UV illumination alters the pretilt angle of alignment layers, a Fresnel zone-distribution hybrid alignment in the homeotropic LC cell can be straightforwardly achieved through UV exposure, yielding a concentric structure of the Fresnel phase LC lens. A remarkable diffraction efficiency of ~31.