Optical communication system compensating for chromatic dispersion and phase conjugate light generator for use therewith

An optical communication system comprising:

• a first single mode optical fiber transmission line for transmitting a first optical signal having an original phase;
• a second single mode optical fiber transmission line;
• and
• an optical chromatic dispersion compensation device, comprising:
• an optical fiber providing a zero-dispersion at a first wavelength, the optical fiber having first and second ends;
• a first terminal for receiving the first optical signal from the first single mode optical fiber transmission line and for inputting the first optical signal to the first end of the optical fiber;
• a light source for outputting to the first end of the optical fiber a pumping light having a wavelength substantially equal to the first wavelength such that the phase of light travelling in the optical fiber is changed from the original phase and a phase conjugate light having a phase which is a conjugate of the original phase is emitted from the second end of the optical fiber;
• and
• a second terminal for receiving from the second end of the optical fiber the phase conjugate light emitted from the second end of the optical fiber, the second terminal being coupled to the second signal mode optical fiber transmission line for outputting the phase conjugate light to the second single mode optical fiber transmission line for travel through the second single mode optical fiber transmission line.

A phase conjugate light generator, comprising:

• a non-linear optical medium;
• a splitter for splitting an optical signal having an original phase into a first polarized component having a first polarization plane and a second polarized component having a second polarization plane perpendicular to the first polarization plane and supplying the first and second polarized components to the non-linear optical medium;
• and
• a light source for outputting to the non-linear optical medium a pumping light having a polarization plane substantially the same as one of the first and second polarization planes such that a phase conjugate light having a phase which is a conjugate of the original phase is generated in the non-linear optical medium.

A phase conjugate light generator, comprising:

• first and second non-linear optical mediums;
• a splitter for splitting an optical signal having an original phase into a first polarized component having a first polarization plane and a second polarized component having a second polarization plane perpendicular to the first polarization plane and supplying the first and second polarized components respectively to the first and second non-linear optical mediums;
• and
• a light source for outputting to the first and second non-linear optical mediums first and second pumping light beams respectively having substantially the same polarization planes as the first and second polarization planes such that the optical signal is transformed in the first and second non-linear optical mediums and first and second phase conjugate light beams are respectively generated in the first and second non-linear optical mediums, the first and second phase conjugate light beams having a phase which is a conjugate of the original phase.

A phase conjugate light generator, comprising:

• an optical fiber having first and second ends;
• a splitter for splitting an optical signal having an original phase into a first polarized component having a first polarization plane and a second polarized component having a second polarization plane perpendicular to the first polarization plane and supplying the first and second polarized components respectively to the first and second ends of the optical fiber;
• and
• a light source for outputting to the first and second ends of the optical fiber first and second pumping light beams respectively having substantially the same polarization planes as the first and second polarization planes such that the first and second polarized components are transformed in the optical fiber into first and second phase conjugate light beams which are emitted from the second and first ends of the optical fiber, respectively, the first and second phase conjugate light beams having a phase which is a conjugate of the original phase.

A phase conjugate light generator, comprising:

• a non-linear optical medium;
• a signal supply for supplying to the non-linear optical medium an optical signal having an original phase;
• and
• a light source for outputting to the non-linear optical medium a pumping light having a polarization which is scrambled such that the optical signal is transformed in the non-linear optical medium and a phase conjugate light is generated in the non-linear optical medium, the phase conjugate light having a phase which is a conjugate of the original phase.

A phase conjugate light generator, comprising:

• a non-linear optical medium;
• a signal supply for supplying to the non-linear optical medium an optical signal saving a polarization which is scrambled and having an original phase;
• and
• a light source for outputting to the non-linear optical medium a pumping light such that the optical signal is transformed in the non-linear optical medium and a phase conjugate light is generated in the non-linear optical medium, the phase conjugate light having a phase which is a conjugate of the original phase.

An optical communication system, comprising:

• a first optical fiber transmission line for transmitting an optical signal having an original phase;
• a phase conjugate light generator for receiving the optical signal from the first optical fiber transmission line, transforming the optical signal and generating a phase conjugate light having a phase which is a conjugate of the original phase;
• and
• a second optical fiber transmission line for receiving the phase conjugate light from the phase conjugate light generator and transmitting the phase conjugate light, the first and second optical fiber transmission lines being selected so that the optical Kerr effect in the first optical fiber transmission line is substantially equal to the optical Kerr effect in the second optical fiber transmission line.

A phase conjugate light generator, comprising:

• a first optical fiber transmission line for transmitting an optical signal having an original phase;
• a phase conjugate light generator comprising:
• a non-linear optical medium connected to the first optical fiber transmission line to receive the optical signal, and
• a light source for outputting to the non-linear optical medium a pumping light so that the optical signal is transformed in the non-linear optical medium and a phase conjugate light is generated in the non-linear optical medium, the phase conjugate light having phase which is a conjugate of the original phase,
• a second optical fiber transmission line for receiving the phase conjugate light from the phase conjugate light generator and transmitting the phase conjugate light, the first and second optical fiber transmission lines being selected so that the optical Kerr effect in the first optical fiber transmission line is substantially equal to the optical Kerr effect in the second optical fiber transmission line.

A phase conjugate light generator, comprising:

• a non-linear optical medium;
• a signal supply for supplying to the non-linear optical medium an optical signal having an original phase and comprising a first optical signal pulse train;
• and
• a light source for outputting to the non-linear optical medium a pumping light pulse train synchronized with the first optical signal pulse train such that the optical signal is transformed in the non-linear optical medium and a phase conjugate light is generated in the non-linear optical medium, the phase conjugate light having a phase which is a conjugate of the original phase, the phase conjugate light comprising a second optical signal pulse train synchronized with the first optical signal pulse train and the pumping light pulse train.

An optical compensation apparatus, comprising:

• a non-linear optical medium;
• a signal supply for supplying to the non-linear optical medium an optical signal having an original phase and comprising a first optical signal pulse train;
• and
• a light source for outputting to the non-linear optical medium a pumping light pulse train having a pumping pulse width, the pumping light pulse train being synchronized with the optical signal pulse train such that the optical signal is transformed in the non-linear optical medium and a phase conjugate light is generated in the non-linear optical medium, the phase conjugate light having a phase which is a conjugate of the original phase, the phase conjugate light comprising a second optical signal pulse train synchronized with the first optical signal pulse train and the pumping light pulse train, the second optical signal pulse train having a pulse width and the pumping pulse width being selected to control the pulse width of the second optical signal pulse train.

An optical communication system, comprising:

• a first optical fiber transmission line for transmitting an optical signal having an original phase and comprising a first optical signal pulse train;
• and
• an optical compensation device including:
• a non-linear optical medium connected to the first optical fiber transmission line to receive the optical signal;
• a light source for outputting to the non-linear optical medium a pumping light pulse train synchronized with the first optical signal pulse train such that the optical signal is transformed in the non-linear optical medium and a phase conjugate light is generated in the non-linear optical medium, the phase conjugate light having a phase which is a conjugate of the original phase, the phase conjugate light comprising a second optical signal pulse train synchronized with the first optical signal pulse train and the pumping light pulse train;
• and
• a second optical fiber transmission line for receiving the phase conjugate light from the non-linear optical medium and for transmitting the phase conjugate light.