A system and method are disclosed for carrying additional information data on
multiplexed
signals which are modulated on different wavelengths. An information code such
as an address or control data for a particular data signal at a selected wavelength
is overlaid on the parallel multiplexed signals. The information code may be overlaid
by attenuation or changing the amplitude of the different signals. A separate marker
channel at a separate wavelength is also multiplexed with the data signals to indicate
the presence of an information code. An optical data detector array is used to
optically determine the encoded address by comparing the signals with light levels
and producing an output when a matching code is detected. The optical data detector
array uses a series of detectors each corresponding to the wavelength of light
signals carrying the information data. The detectors each have two photo detectors
which are wired in parallel with each other to produce a voltage output when different
light levels are detected on the two photo detectors. Using the information codes,
an optical buffer may be realized which allows true optical switching of a data
signal on detection of a matching information code. Alternatively, optical signals
may be cross connected to balance data traffic through a fiber optic cable.
