Two-wavelength WDM Analog CATV transmission with low crosstalk

A method of transmitting wavelength-division-multiplexed signals over an optical fiber, the method comprising the steps of:

• providing a plurality of fiber optic sources, one of said plurality of fiber optic sources producing an output having a first wavelength and another one of said plurality of fiber optic sources producing an output having a second wavelength, the difference between the first and second wavelengths being approximately 2.2 nanometers;
• modulating the first and second outputs of the fiber optic transmitters with signals to produce first and second modulated outputs;
• multiplexing the first and second modulated outputs to produce a wavelength-division-multiplexed output;
• providing an optical fiber having a transmitter end and a receiver end, launching the wavelength-division-multiplexed output into the transmitter end of the optical fiber;
• and
• dithering at least one of the fiber optic transmitters to reduce crosstalk between the signal at the receiver end of the optical fiber.

An apparatus for transmitting signals over an optical fiber, said apparatus comprising:

• a plurality of fiber optic sources producing a plurality of wavelengths, a first one of said plurality of fiber optic sources producing a first output having a first wavelength and a second one of said plurality of fiber optic sources producing a second output having a second wavelength, the difference between the first wavelength and the second wavelength being approximately 2.2 nanometers;
• means for modulating the first and second outputs of the fiber optic sources with signals to produce first and second modulated outputs;
• means for combining the first and second modulated outputs to produce a wavelength-division-multiplexed output, and an optical fiber having a transmitter end and a receiver end, the transmitter end of the fiber optic cable being adapted to receive the wavelength-division-multiplexed output;
• and
• means for applying a dither to at least one of the fiber optic sources such that the dither reduces crosstalk in the analog video signals of the wavelength-division-multiplexed output at the receiver end of the optical fiber;
• wherein the difference of about 2.2 nanometers between the first wavelength and the second wavelength reduces crosstalk noise in the signals of the wavelength-division-multiplexed output at the receiver end of the optical fiber.