An optical signal noise reduction device and method, where optical control signals
are input into a first ring optical fiber, so that optical signals propagates clockwise
and counter-clockwise in the optical fiber, with optical control signals propagating
either clockwise or counter-clockwise in the first ring optical fiber. Optica signals
propagating in the same direction as the optical control signals are affected with
cross phase modulation with the optical control signals, while optical signals
propagating in the opposite direction as the optical control signals are not affected
with cross phase modulation with the optical control signals. The two kinds of
the optical signals are then interfered with each other at the optical output to
reduce noise of the optical.
