Simple optical profiling of complex guiding structures

Working with complex guiding structures such as holey fibers requires coupling light into the input face of the structure. We use a simple in vivo technique to determine the scale, morphology, and orientation of the input cleave of the fiber without resorting to separate and more complex methods like optical imaging or scanning electron microscopy. Further, after obtaining the transverse scan of the fiber tip one can precisely position the focal spot anywhere relative to the fiber structure.