Novel and significant results on the non-recirculating delay line with a fiber loop

We show theoretically and experimentally that the behavior of the non-recirculating delay line with a fiber loop (NDLL) cannot be explained by assuming intensity summation over the whole structure even though the fiber delays are much bigger than the source coherence time (incoherent operation regime). These results have important implications in the analysis and design of incoherent fiber-optic filters incorporating loops.