This paper presents a new optical circuit that performs both pulse compression and frame synchronization and retiming.
Our design aims at directly multiplexing several 10G Ethernet data packets (frames) to a high-speed OTDM link. This
scheme is optically transparent and does not require clock recovery, resulting in a potentially very efficient solution. The
scheme uses a time-lens, implemented through a sinusoidally driven optical phase modulation, combined with a linear
dispersion element. As time-lenses are also used for pulse compression, we design the circuit also to perform pulse
compression, as well. The overall design is: (1) Pulses are converted from NRZ to RZ; (2) pulses are synchronized,
retimed and further compressed at the specially designed time-lens; and (3) with adequate optical delays, frames from
different input interfaces are added, with a simple optical coupler, completing the OTDM signal generation. We
demonstrate the effectiveness of the design by laboratory experiments.
A statistical model of the aggregation operation in an optical packet based network interface is presented. The operation
aggregates client-layer packets into optical slots, and includes a timeout parameter to limit the maximum delay.
Aggregation serves the purpose of providing an efficient filling of the large optical slots with smaller packets from the
client layer. The model will be utilized to derive an optimal choice of timeout parameter that will lead to an efficient
utilization of the optical packets.