Compact 1 Â 2 multimode fiber optic switches are demonstrated using nematic liquid crystals, a polarization beamsplitter and polarizers. Different structures are proposed for showing that even using NLC with low polarization crosstalk, the device working can be improved using alternative configurations. The switch output ports exhibit an optical interchannel crosstalk less than )22 dB, 7 dB fiber to fiber loss and simultaneous operation at 650 and 850 nm with a low power consumption. Applications of the switch include coarse WDM and optical fiber sensor networks.
Abstract-Optical fiber sensor networks are evolving rapidly. They are used because of the inert nature of optical fibers allowing no electromagnetic interference and safe applications in inflammable atmospheres; other relevant characteristics are their low weights and wide bandwidths as a transmission medium. In any case, it is very interesting to have specific components such as optical routers for selecting a certain path in a network with no optical to electrical and electrical to optical conversions. In this paper, we propose an all-optical router based on liquid crystals, polarizers, and a spatial split polarization beam splitter. The implemented device is designed to operate with visible light and it has been tested with plastic optical fibers. It has a crosstalk of 14 dB between selected ON channels and nonoperative OFF channels and 11-dB insertion losses. An average switch time of 100 ms is measured. The device checks the optical power level in each channel and, in case of failure, automatically switches to an operative channel while an alarm is activated.Index Terms-Liquid crystal cell, optical router, sensor network.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.