Wavelength multiplexed optical communications system and method

An optical fiber communications system comprising:

• a communication loop defined by a birefringent light guiding optical fiber that preferentially supports light propagated in first and second characteristic states corresponding, respectively, to first and second polarization states;
• means for introducing system wide carrier light in the first characteristic state into said loop for propagation therein wherein said carrier introducing means comprises a light source for generating light at a selected frequency and birefringent resonator means coupled to said light source and said loop for resonantly supporting light in the first state prior to introducing the carrier light into said loop;
• and
• terminal means coupled to said loop for removing a portion of the carrier light, for modulating and shifting the carrier light to the second characteristic state, and for returning the modulated and state shifted light to said loop for propagation therein.

An optical fiber communications system comprising:

• a communications loop defined by a birefringent light guiding optical fiber that preferentially supports light propagated in first and second characteristic states corresponding, respectively, to first and second polarization states;
• means for introducing system wide carrier light in the first characteristic state into said loop for propagation therein wherein said carrier introducing means comprises:
• a light source for generating light at a selected frequency;
• a birefringent optical transfer link coupled to said light source;
• a resonant cavity structure coupled between said transfer link and said communications loop;
• and
• means for controlling the frequency of said resonant cavity coupled between said transfer link and said communications loop;
• and
• terminal means coupled to said loop for removing a portion of the carrier light, for modulating and shifting the carrier light to the second characteristic state, and for returning the modulated and state shifted light to said loop for propagation therein.

An optical fiber communications system comprising:

• a communications loop defined by a birefringent light guiding optical fiber that preferentially supports light propagated in first and second characteristic states corresponding, respectively, to first and second polarization states;
• means for introducing system wide carrier light in the first characteristic state into said loop for propagation therein;
• and
• terminal means coupled to said loop for removing a portion of the carrier light, for modulating and shifting the carrier light to the second characteristic state, and for returning the modulated and state shifted light to said loop for propagation therein, and wherein said terminal means comprises:
• resonator means for removing a portion of the light propagated in said loop in the first polarized state;
• and
• modulator means including an electrically responsive birefringent material through which the removed light is passed to effect a state shift and modulation thereof in response to an electrically applied modulation signal.

An optical fiber communications system comprising:

• a communications loop defined by a birefringent light guiding optical fiber that preferentially supports light propagated in first and second characteristic states corresponding, respectively, to first and second polarization states;
• means for introducing system wide carrier light in the first characteristic state into said loop for propagation therein;
• and
• terminal means coupled to said loop for removing a portion of the carrier light, for modulating and shifting the carrier light to the second characteristic state, and for returning the modulated and state shifted light to said loop for propagation therein, and wherein said terminal means comprises:
• a resonant cavity structure coupled to said communications loop;
• a birefringent optical transfer link coupled to said resonant cavity structure and having an input/output port;
• modulator means coupled to the input/output port of said transfer link and including an electrically responsive birefringent material through which light is passed to effect a state shift and modulation thereof in response to an electrically applied modulation signal;
• and
• means for controlling the frequency of said resonant cavity structure coupled between said transfer link and said communications loop.

A method of optically conveying information, comprising the steps of:

• propagating light in a first characteristic state along an optical pathway capable of preferentially supporting optical energy propagated in either a first characteristic state or a second characteristic state corresponding, respectively, to first and second polarization states;
• removing a portion of the first characteristic state light from the optical pathway;
• modulating the removed light with information, shifting the light to the second state and shifting the frequency of the removed light;
• and
• introducing the modulated and state switched optical energy into the optical pathway for propagation thereon.

A method of optically conveying information, comprising the steps of:

• propagating light in a first characteristic state along an optical pathway capable of preferentially supporting optical energy propagated in either a first characteristic state or a second characteristic state;
• removing a portion of the first characteristic state light from the optical pathway;
• modulating the removed light with information and shifting the light to the second state, wherein said modulating and state shifting step further comprises shifting the frequency of the removed light;
• introducing the modulated and state switched optical energy into the optical pathway for propagation thereon, wherein said propagation step further comprises propagating said light in a first direction along said optical pathway and said introducing step further comprises introducing the state shifted light onto said optical pathway in a direction opposite to said first direction;
• and
• removing a portion of the second characteristic state light and demodulating the removed light to recover the original information signal.

An optical fiber communications system comprising:

• a communications loop defined by a birefringent light guiding fiber that preferentially supports light propogated in first and second characteristic states corresponding, respectively, to first and second polarization states;
• means for introducing system wide carrier light in the first characteristic state into said loop for propagation therein;
• and
• terminal means coupled to said loop for removing a portion of the carrier light, for modulating and shifting the carrier light to the second characteristic state, and for returning the modulated and state shifted light to said loop for propagation therein wherein said terminal means returns modulated and state shifted light to said loop at a frequency different from the carrier light introduced by said carrier introducing means.