Abstract

A multicore optical fiber having a plurality of cores positioned across the diameter of a common cladding can be so optimized to respond to either temperature or strain by the selection of materials, spacing and shape of the cores in the fiber. The cross-talk between adjacent cores in the fiber changes in response to either a change in temperature or a strain along the length of the fiber. The temperature, strain or pressure change, can be determined by measuring the relative intensity of light emerging from the different cores of the fiber. If the fiber is optimized to respond to temperature change, then a high degree of temperature sensitivity can be provided over a large unambiguous range. Alternatively, cross-talk can be made temperature insensitive so that the intensity pattern of light emerging from the various cores in the fiber is only a function of the strain exerted on the fiber.