Novel On-Line Sedimentation Analyzer

The design and development of a novel vibrating reed technique for on-line measurement of the sedimentation kinetics of two-phase dispersions is described. The feasibility of operation of the analyzer has been successfully verified in conjunction with a variety of model and industrially relevant systems. The former include mono- and polydisperse glass ballotini/water mixtures with solids particle sizes and concentration ranges of 55-200 μm and 1.75-2.81% (v/v), respectively. Measured settling velocities are in good accord with those obtained from direct visual observation of suspension-clear liquid interfaces. The industrially relevant systems include agglomerated kaolin/water suspensions with solids concentrations as high as 20% (v/v) and oil/water emulsions with light phase concentrations in the range 30-50% (v/v). Copyright 2000 Academic Press.     

Improving the Performance of All-Optical Wavelength Converters Using Fiber Gratings

We show that spectral filtering using a fiber Bragg grating as an optical discriminator improves the performance of semiconductor optical amplifier (SOA) wavelength converters. This technique increases the operation speed and reduces the data patterning effect of SOAs for non-return-to-zero (NRZ)operation. For return-to-zero (RZ) operation the fiber grating increases extinction ratio and preserves the data polarity. We use this technique to obtain error-free wavelength conversion of NRZ data at 10 Gb s in an SOA with 6 GHz dynamic bandwidth. We also use the SOA fiber grating to convert RZ data at 10 Gb s and show that the converted pulses can propagate error free over 20,000 km in a dispersion-managed system.