Opening OPTICAL FIBERS Without Sacrificing Robustness

Access to the core of an optical fiber is required for many applications, including evanescent wave sensing. Direct access to the core of conventional optical fibers has been achieved typically by removing the fiber cladding by etching or by tapering anywhere along the fiber. These processes leave the device fragile and, thus, limited in length because of the fragility. A robust alternative is the micro-structured optical fiber (Figure 1). These fibers are like drinking straws, with holes running along the length of the fiber forming the cladding, through which liquid or gas can be sucked up. Because the fiber jacket and cladding remain intact, the microstructured fibers suffer no limitations resulting from weakness.