  Ultrahigh-speed optical transmission technology, such as optical time domain
multiplexing or optical signal processing is a key point for increasing the
communication capacity. The system performances are strongly related to pulse
properties. We present an original method dedicated to short pulse-shape
characterization with high repetition rate using standard optical
telecommunications equipments. Its principle is based on temporal measurement
of the contrast produced by the beating of two delayed optical pulses in a high
bandwidth photo detector. This technique returns firstly reliable information
on the pulse-shape, such as pulse width, shape and pedestal. Simulation and
experimental results evaluate the high-sensitivity and the high-resolution of
the technique allowing the measurement of pulse extinction ratio up to 20 dB
with typical timing resolution of about 100 fs. The compatibility of the
technique with high repetition rate pulse measurement offers an efficient tool
for short pulse analysis.
