Optical wavelength ratiometric monitoring system for data centre CWDM applications

The development of the internet and the subsequent increase in the quantity of connected devices in recent years has given rise to an explosion in demand of data traffic across telecommunication networks. Converged networks deliver high speed bit rates for the purpose of streaming videos, downloading music files and communicating over the internet; voice over internet protocol (VOIP). Further additional data traffic growth stemming from the upsurge in the amount of `tweets' and instant messages (IM) created as well as emails written and cloud storage, has led to a demand for the construction of much larger data centres, which have the capacity to store and transmit this increased data. The physical location of these larger data centres is often governed by their proximity to the source of cheap electrical power and favourable climate conditions. In this paper, the development of an optical fibre monitor is examined. The main attributes of the system will be its ability to monitor both the signal optical power and an individual wavelength within a live coarse wavelength division multiplexing (CWDM) fibre optic installation without causing any disturbance to the link. In response to the prolific growth of larger data centres and the increased demand for CWDM links to service them the onus to develop a low cost, flexible and reliable alternative to the spectrum analyser for the purpose of monitoring has intensified.