Polymer Fibers for Nonlinear Optics

Abstract

Abstract : The goal of our research is to assess the possibility of making an ultrafast all-optical switching device. This require the preliminaries of doing materials processing, materials characterization, and making all-device component structures such as single mode fibers. With these in hand, a demonstration all-optical switching device can be made. Such a device would be the first step towards ultrafast switching systems for the information highway and all-optical computing applications. Our work is motivated by the demonstration of an all-optical switch in a silica optical fiber. While this device displays all essential switching functions, the small materials nonlinearity requires fibers 1 km lengths, resulting in long latency periods. Because we have the ability to make polymer fibers with optical nonlinearities that are three orders of magnitude larger, we can make sub-meter length devices. As an ongoing process, have continually improved the fiber drawing process, have characterized crucial material properties, and have improved on designs of optical switches that take advantage of the polymer fiber's nonlinearity. We have demonstrated the fabrication of fibers with cores that are less than 10 micrometers in diameter, have shown that these can support single mode light-guiding (required for optimum device operation), and that they do not depolarize light: an important property for devices that require polarization preserving fibers. The Sagnac interferometer experiment had been used to measure the switching efficiency in a single mode polymer fiber and a true all-optical switching device has been built and has given evidence of all-optical switching.