Method of making Mach-Zehnder interferometric device with composite fibers

摘要

A Mach-Zehnder wavelength selective device is made using one or more composite optical fibers (206) each incorporating a phase shft region (210) having one effective refractive index spliced between coupling regions having a different effective refractive index. The optical path length difference or phase delay induced by each such composite fiber is a linear function of the length of the phase shift region.