OPTICAL FIBER MACH-ZEHNDER INTERFEROMETER FABRICATED WITH ASYMMETRIC COUPLERS

摘要

An asymmetric optical fiber Mach-Zehnder interferometer has first and second optical fibers connected at a first coupling region and a second coupling region. The first and second optical fibers form two interfering arms between the first and second coupling regions. To form the asymmetry, the propagation constant in a portion of the first optical fiber in one of the coupling regions differs from the propagation constant in a portion of the second optical fiber in that coupling region. The asymmetric structure provides 30 dB isolation over a greater wavelength span.