Single wavelength bidirectional optical fiber communication link

A bidirectional communication link comprising:

• an optical fiber having a first and a second end;
• first transmitter means for generating a first optical carrier of a first wavelength;
• first modulator means for modulating said first optical carrier with a first modulating signal confined to a first frequency spectrum;
• second transmitter means for generating a second optical carrier at said first wavelength;
• second modulator means for modulating said second optical carrier with a second modulating signal confined to a second frequency spectrum not overlapping said first frequency spectrum;
• first receiver means for extracting said first modulating signal from said first optical carrier;
• second receiver means for extracting said second modulating signal from said second optical carrier;
• first coupling means for coupling said first transmitter means and said second receiver means to said first end of said optical fiber;
• and
• second coupling means for coupling said second transmitter means and said first receiver means to said second end of said optical fiber.

In a system including a vehicle, a control station, and an optical fiber therebetween, a bidirectional communication link comprising:

• bobbin means for coupling a first end of said optical fiber to said vehicle;
• first means, included within said vehicle, for launching a first optical carrier of a first wavelength onto said fiber, said first launching means including means for impressing a first modulating signal confined to a first frequency spectrum upon said first carrier;
• second means, included within said control station, for launching a second optical carrier of said first wavelength onto said fiber at a second end thereof, said second launching means including means for impressing upon said second carrier a second modulating signal confined to a second frequency spectrum not overlapping said first spectrum;
• first receiver means, included within said vehicle, for extracting said first modulating signal from said first optical carrier;
• and
• second receiver means, included within said control station, for extracting said second modulating signal from said second optical carrier.

In a system including a vehicle, a control station, and an optical fiber therebetween, a bidirectional communication link comprising:

• bobbin means for coupling a first end of said optical fiber to said vehicle;
• first transmitter means, included within said vehicle, for generating a first optical carrier of a first wavelength;
• first modulator means for modulating said first optical carrier with a first modulating signal confined to a first frequency spectrum;
• second transmitter means, included within said control station, for generating a second optical carrier at said first wavelength;
• second modulator means for modulating said second optical carrier with a second modulating signal confined to a second frequency spectrum not overlapping said first frequency spectrum;
• first receiver means, included within said control station, for extracting said first modulating signal from said first optical carrier;
• second receiver means, included within said vehicle, for extracting said second modulating signal from said second optical carrier;
• first coupling means for coupling said first transmitter means and said second receiver means to said bobbin means;
• and
• second coupling means for coupling said second transmitter means and said first receiver means to a second end of said optical fiber.

A method of contemporaneously transmitting signals having optical carriers of a common wavelength along an optical fiber comprising the steps of:

• a) generating a first optical carrier of a first wavelength;
• b) modulating said first optical carrier with a first modulating signal confined to a first frequency spectrum;
• c) launching said modulated optical carrier onto said optical fiber at a first end thereof;
• d) generating a second optical carrier at said first wavelength;
• e) modulating said second optical carrier with a second modulating signal confined to a second frequency spectrum
• f) launching said second modulated optical carrier onto said optical fiber at a second end thereof;
• g) extracting said first modulating signal from said first optical carrier;
• h) extracting said second modulating signal from said second optical carrier.