Peter Edward Barnsley

Inter-channel crosstalk phenomena in optical time division multiplexed switching networks

The nature of inter-channel crosstalk arising in OTDM switching networks formed from imperfectly isolated 2/spl times/2 crosspoints and optical delay lines is investigated and a novel classification is identified. It is shown that the mixing of crosstalk and signal waveforms which are either, a) mutually coherent or, b) incoherent and (optical) frequency matched to within the receiver bandwidth, may result in intensity noise and far greater performance degradation than for c) incoherent signals whose optical beat frequency exceeds the receiver bandwidth. Initial experimental studies indicate that crosspoint isolation <-15 dB is required if undilated networks containing more than four crosspoints are to be realised.<<ETX>>

Architectures for optical TDM switching

This paper describes some novel architectures for optical TDM switching, and an experimental system working at 720 Mb/s; this includes a complete BER characterization. The architectures are composed of 2 X 2 optical switches and delay lines. The trade-offs between the various factors affecting their design are explored, and a wide range of architectures are presented suitable for different applications.

Absorptive and Dispersive Switching in a Three Region InGaAsP Semiconductor Laser Amplifier at 1·57 μm

Abstract The absorptive and dispersive nonlinear characteristics of a novel three region InGaAsP laser amplifier are presented. Nonlinear amplification is seen over a 15 nm wavelength range. The effects of input power, signal frequency detuning and gain on the nonlinear characteristics are investigated. A 12 GHz transmission bandwidth for the absorptive nonlinearity is found. The device exhibited 16 dB nonlinear gain with a minimum nonlinear threshold of − 25 dBm. The rise time for the nonlinear switching was <350 ps, showing that this type of device has application to high-data-rate optical transmission systems.