We determine group index and group velocity dispersion (GVD) of SOI single-mode strip waveguides (photonic wires) with 525x226nm cross-section over the entire telecommunication bandwidth by employing an integrated Mach-Zehnder interferometer. The measured GVD yields 4400 ps/(nm*km) at 1550 nm and exceeds that of standard single-mode fibers by almost three orders of magnitude. In the photonic wires the GVD is mainly determined by strong light confinement rather than by material dispersion. Our results indicate that despite this high GVD, dispersion-induced signal impairment is negligible in photonic circuits for data rates up to 100-Gb/s and total waveguide lengths as long as about 1 meter. The measured group index and GVD are used as benchmarks to compare model calculations originating from four different theoretical methods.

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The phase dynamics that occur in bulk InGaAsP-InP semiconductor optical amplifiers (SOAs) in response to picosecond pulse excitations at 10 and 40 GHz are studied experimentally and numerically for various amplifier lengths. The time dependencies of the phase changes and of the absolute gain of the amplifier are measured simultaneously. The total phase shifts induced by 1.5-ps pulses at 10 GHz are higher than /spl pi/ in SOAs with active region lengths between 0.5 and 2 mm and exceed 2/spl pi/ in a 1.5-mm-long amplifier. Phase shifts above /spl pi/ are measured at 40 GHz in 1.5- and 2-mm-long SOAs. The dependence of the total phase shift on the amplifier bias current and length and on pump pulse energy is investigated. Numerical simulations based on a comprehensive time-domain SOA model allow us to confirm the experimental results for a wide range of amplifier parameters. In particular, SOAs with lengths up to 5 mm have been modeled, and the calculations suggest that the maximum phase shifts occur in amplifiers of approximately 2-mm length. The phase dynamics measurements are illustrated at the example of an optical time division multiplexing add-drop multiplexer, based on a SLALOM switch, gated by 10- or 40-GHz control pulses. We find that simultaneous good dropping and clearing is possible if the length and the operating conditions of the SOA in the switch are chosen such as to induce a full /spl pi/ phase shift

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