Abstract: In a frequency-controlled optical switching system, a first light source generates a data signal having a first wavelength. A second light source generates a control signal having a second wavelength, which is different from the first wavelength. A first wavelength division multiplexer, optically coupled to both the first light source and the second light source, couples an optical signal received from the first light source and an optical signal received from the second light source onto a single optical fiber. A second wavelength division multiplexer, optically coupled to the single optical fiber and spaced apart from the first wavelength division multiplexer, separates a signal having the first wavelength from a signal having the second wavelength. The second wavelength division multiplexer couples the signal having the first wavelength onto a second optical fiber and couples the signal having the second wavelength onto a third optical fiber.