Mixed fiber infrastructures in long haul WDM-transmission

The existing global fiber infrastructure consists of different fiber types like standard single-mode fiber (G.652) and non-zero dispersion shifted fiber (NZDSF). With the introduction of transparent networking, however, optical communication signals when transmitted over such inhomogeneous fiber links, consisting of different fiber types, may exhibit unpredictable transmission performance. In an example of such an inhomogeneous fiber network, consisting of G.652 and CorningÒ LEAFÒ fiber, it is shown that by optimizing the transmission performance of the individual fiber sections, transmission over inhomogeneous network links with a mixed fiber infrastructure can be performed without incurring any additional penalties. Long-haul 10 Gb/s NRZ WDM transmission over standard singlemode fiber, NZDSF and a mixed fiber infrastructure is simulated and experimentally demonstrated. For optimized operation parameters it is demonstrated that 2500 km error-free transmission is feasible for all scenarios without use of FEC and Raman-amplification

Vibration-insensitive temperature sensing system based on fluorescence decay and using a digital processing approach

A fluorescence-based temperature sensor system using a digital signal processing approach has been developed and evaluated in operation on a working automotive engine. The signal processing approach, using the least squares method, makes the system relatively insensitive to intensity variations in the probe and thus provides more precise measurements when compared to a previous system designed using analogue phase-locked detection. Experiments carried out to determine the emission temperatures of a running car engine have demonstrated the effectiveness of the sensor system in monitoring exhaust temperatures up to 250oC, and potentially highe