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The development of the information society will require the introduction of high-capacity transport networks with high performance and low cost. There are currently two ACTS (Advanced Communications Technologies and Services program launched by the European Commission) projects addressing specifically the problem of trans-European optical transport networks using WDM (wavelength division multiplexing). Important issues addressed are the high capacity transmission on existing fiber infrastructure and the introduction of flexibility in the network through the use of optical cross-connects. If these networks become a reality, they could drastically change the evolution of both telecommunication and computer networking because of their transparency and the abundance of inexpensive bandwidth.

In this paper we give experimental evidence that the thickness of a layer of silicon stripped by anodic oxidation is solely dependent on the anodically grown thickness of the oxide and is independent of the electrolyte and of other parameters of the experiment. A correlation is established between the thickness of a stripped layer of silicon and that of the oxide. This relation may be used to determine profiles in silicon by means of anodic oxidation.

4 cases of extrapyramidal disturbances, observed in children with Metoclopramid-medication, are reported. These side-effects may occur already at normal therapeutic dosage, especially in the young patient. The side-effects are reversible, and respond easily to i.v. injection or peroral application of anti-parkinsonian drugs, less severe cases may subside by withdrawal of the drug. The therapeutic use in the pediatric field must be strictly indicated because of the special disposition of children to the side-effects described above.

In high performance SAW TV-IF filters multistrip couplers are used to suppress unwanted spurious bulk mode transmission. Small maximum finger overlap is chosen to keep filter cost low due to small substrate square dimensions. Because of the small apertures diffraction becomes severe on 128' rotated Y-cut lithium-niobate. As recently published scanning electron microscope investigations show, parts of the waves launched by the apertures of the input transducer are spread directly into the output transducer. Experiment shows that these detected spurious waves are only about 40 to 50 dB down compared to midband transmission. This is perfectly verified by calculations using the p arabolic anisotropic diffraction formulas. Using a simple basic theory, diffraction effects in filters using multistrip couplers are taken into consideration in filter analysis. Experimental results are in good agreement with t heo ry .

Short pulses of surface acoustic waves are launched efficiently by an inline assembly of several finger-pair interdigital transducers, which are connected to successive taps of an electrical delay line, where the electrical time lag between two taps is equal to the acoustic delay between corresponding transducers.