An optical signal processor comprises a first input terminal for a pulse
signal light with a signal wavelength, a second input terminal for a probe
light with, probe wavelength different from the signal wavelength, a first
splitter to split the probe light into two portions, an XPM optical device
to modulate the one portion of the split output lights from the splitter,
a second splitter to split light with the probe wavelength phase-modulated
by the XPM optical device into two portions, a first combiner to combine
the other portion of the split output lights from the first splitter with
the one portion of the split output lights from the second splitter, and a
second combiner to combine the other portion of the split output lights
from the second splitter with the output light from the first combiner.
