High-resolution zero-dispersion wavelength mapping in single-mode fiber

We present a new noninvasive technique for measuring the spatial variation of the zero-dispersion wavelength (λ0) in single-mode fibers. This technique uses low-power continuous-wave lasers and is simple to implement. When applying this technique to dispersion-shifted fibers, we can resolve subnanometer fluctuations in λ0 with a potential spatial resolution of better than 100 m. We also discuss and show the limits of this and other techniques that arise from polarization-mode dispersion in the fibers. © 1998 Optical Society of America.