Comb filters based on polarization rotation in photosensitive optical fibers

摘要

We report on the fabrication of comb filters which operate on the principle of linear polarization rotation through the twisting of the birefringent axes of photosensitive elliptical-core fibers by UV radiation. The polarization coupling spectrum of these filters consists of a series of narrow resonances which are roughly equally spaced in frequency and which extend over the entire single-mode frequency range of the fiber. Some applications of these structures are also discussed.