Abstract: This paper reviews the work performed under the
European ESPRIT project DO_ALL (Digital OpticAL Logic
modules) spanning from advanced devices (semiconductor optical
amplifiers) to all-optical modules (laser sources and gates) and
from optical signal processing subsystems (packet clock recovery,
optical write/store memory, and linear feedback shift register) to
their integration in the application level for the demonstration of
nontrivial logic functionality (all-optical bit-error-rate tester and
a 2 2 exchange–bypass switch). The successful accomplishment
of the project˘s goals has opened the road for the implementation
of more complex ultra-high-speed all-optical signal processing
circuits that are key elements for the realization of all-optical
packet switching networks.
Abstract: A novel method for the multiplication of the repetition
rate of full duty-cycle return-to-zero optical sources is presented.
It employs the memory property of a Fabry–P{\'e}rot filter
for the multiplication task, combined with the gain saturation of a
semiconductor optical amplifier for amplitude equalization. This
concept has been applied to quadruplicate the rate of a distributed
feedback laser source operating at 10 GHz.
Abstract: We present recent advances in multi-wavelength, power-equalized laser sources that incorporate a semiconductor optical amplifier (SOA) and simple optical filters, such as Lyot-type and Fabry-Perot, for comb generation. Both linear and ring-cavity configurations are presented, and single-pass opticalfeedback technique is proposed to improve the performance in terms of the number of simultaneously oscillating lines and output channel power equalization. This technique resulted in a broadened oscillating spectrum of 52 lines spaced at 50 GHz, power-equalized within 0.3 dB. Finally, a simplified version that uses only an uncoated SOA for both gain and comb generation is demonstrated.