Abstract: We demonstrate an all-optical clock and data recovery
circuit for short asynchronous data packets at 10-Gb/s line
rate. The technique employs a Fabry–P{\'e}rot filter and an ultrafastnonlinearinterferometer (UNI) to generate the local packet
clock, followed by a second UNI gate to act as decision element,
performing a logical AND operation between the extracted clocks
and the incoming data packets. The circuit can handle short
packets arriving at time intervals as short as 1.5 ns and arbitrary
phase alignment.
Abstract: This paper presents a theoretical and experimental
analysis of saturated semiconductor optical amplifier (SOA)-based
interferometric switching arrangements. For the first time, it is
shown that such devices can provide enhanced intensity modulation
reduction to return-to-zero (RZ) formatted input pulse trains,
when the SOA is saturated with a strong continuous-wave (CW)
input signal. A novel theoretical platform has been developed in
the frequency domain, which reveals that the intensity modulation
of the input pulse train can be suppressed by more than 10 dB at
the output. This stems from the presence of the strong CW signal
that transforms the sinusoidal transfer function of the interferometric
switch into an almost flat, strongly nonlinear curve. This
behavior has also been verified experimentally for both periodically
and randomly degraded, in terms of intensity modulation,
signals at 10 Gb/s using the ultrafastnonlinearinterferometer as
the switching device. Performance analysis both in the time and
frequency domains is demonstrated, verifying the concept and its
theoretical analysis.
Abstract: Digital optical logic circuits capable of performing bit-wise signal processing are critical building blocks for the realization of future high-speed packet-switched networks. In this paper, we present recent advances in all-optical processing circuits and examine the potential of their integration into a system environment. On this concept, we demonstrate serial all-optical Boolean AND/XOR logic at 20 Gb/s and a novel all-optical packet clock recovery circuit, with low capturing time, suitable for burst-mode traffic. The circuits use the semiconductor-based ultrafastnonlinearinterferometer (UNI) as the nonlinear switching element. We also present the integration of these circuits in a more complex unit that performs header and payload separation from short synchronous data packets at 10 Gb/s. Finally, we discuss a method to realize a novel packet scheduling switch architecture, which guarantees lossless communication for specific traffic burstiness constraints, using these logic units.