Design of Identification Fibers With Individually Assigned Brillouin Frequency Shifts for Monitoring Passive Optical Networks

New OTDR Measurement and Monitoring Techniques

“…Integrating a 1650nm reflective coating inside the ONT might be the best answer in terms of cost but shows some drawbacks like the ambiguity on the demarcation point or the extra-cost on devices that are already under strong price pressure. There have been various attempts made over the years to propose alternative solutions to reduce the cost either by using other principles more or less complex end of fiber marking principles [5] or directly by removing the need to mark the end of fiber, but today, the deployed solutions use fiber Bragg grating reflector and in some cases thin film filter reflectors.…”

Recent research and development of optical fiber monitoring in communication systems

“…The above problem is widely recognized as a research topic of interest in optical fiber monitoring. Many approaches have been reported including the multi-wavelength OTDR with wavelength dependent devices [10,11] and Brillouin OTDR with devices that have different Brillouin frequency shifts [12]. However, these techniques require additional optical components or changes to the optical fiber itself.…”

In-Service Line Monitoring for Passive Optical Networks

“…Figure 5 shows that the design of the BFS for optical fibers depends on the GeO 2 and F dopant concentrations in the fiber core. GeO 2 and F were used to fabricate the identification fibers because as dopants their effects on the refractive index are opposite, but their effects on the BFS are the same, and they are also the most widely used dopants (Iida, et al, 2007). Assuming the maximum BFS separation that we can design is 1.5 GHz and Δν is 120 MHz, we can realize up to 13 kinds of BFS assigned fiber.…”