Optimized optical transmission system for high capacity transmission

An optical transmission system, comprising:

• an optical transmitter for generating an optical signal;
• an optical transmission line for transmitting the optical signal generated by the optical transmitter;
• an optical receiver for recognizing the optical signal transmitted over the optical transmission line;
• and
• characteristic adjusting means for adjusting at least either a characteristic value of the optical signal or a characteristic value of the optical transmission line to match the characteristic of the optical signal to that of the optical transmission line,
• wherein the optical transmission line includes optical fibers, and
• the characteristic adjusting means includes a variable dispersion compensation having a variable dispersion value, installed on the optical transmission line, for compensating for the wavelength dispersion characteristic of the optical fibers by adjusting the variable dispersion value as the characteristic value of the optical transmission line, and
• the optical transmission line further includes an optical amplifier, installed between the optical fibers for amplifying the optical signal transmitted through the optical fibers, and
• the wavelength of the optical signal is spaced apart from the zero dispersion wavelength of the optical fiber just enough to suppress four-wave mixing between spontaneous emission from the optical amplifier and the optical signal.

An optical transmission system comprising:

• an optical transmitter for generating an optical signal;
• an optical transmission line for transmitting the optical signal generated by the optical transmitter;
• an optical receiver for recognizing the optical signal transmitted over the optical transmission line;
• and
• characteristic adjusting means for adjusting at least either a characteristic value of the optical signal or a characteristic value of the optical transmission line to match the characteristic of the optical signal to that of the optical transmission line,
• wherein the characteristic adjusting means includes variable-chirping means for adjusting as the characteristic value of the optical signal the amount of prechirping to be given to the optical signal generated by the optical transmitter.

An optical transmission system comprising:

• an optical transmitter for generating an optical signal;
• an optical transmission line for transmitting the optical signal generated by the optical transmitter;
• an optical receiver for recognizing the optical signal transmitted over the optical transmission line;
• characteristic adjusting means for adjusting at least either a characteristic value of the optical signal or a characteristic value of the optical transmission line to match the characteristic of the optical signal to that of the optical transmission line;
• and
• transmission characteristic measuring means for measuring a transmission characteristic by evaluating the quality of the optical signal recognized by the optical receiver, wherein
• the characteristic adjusting means adjusts at least either the characteristic value of the optical signal or the characteristic value of the optical transmission line so that the transmission characteristic measured by the transmission characteristic measuring means is best adjusted.

An optical transmission system comprising:

• an optical transmitter for generating an optical signal;
• an optical transmission line for transmitting the optical signal generated by the optical transmitter;
• an optical receiver for recognizing the optical signal transmitted over the optical transmission line;
• characteristic adjusting means for adjusting at least either a characteristic value of the optical signal or a characteristic value of the optical transmission line the characteristic of the optical signal to that of the optical transmission line;
• temperature evaluating means for evaluating the temperature of the optical transmission line in order for the characteristic adjusting means to adjust at least either the characteristic value of the optical signal or the characteristic value of the optical transmission line according to the change of the temperature of the optical transmission line.

An optical transmission system comprising:

• an optical transmitter for generating an optical signal;
• an optical transmission line for transmitting the optical signal generated by the optical transmitter;
• an optical receiver for recognizing the optical signal transmitted over the optical transmission line;
• nonlinear effect reducing means for smoothing variations of the strength of the optical signal transmitted through the optical transmission line, the nonlinear effect reducing means including means for providing optical signal wavelength dispersion sufficient to reduce a nonlinear effect;
• and
• means for compensating for the wavelength dispersion caused by the wavelength dispersion providing means,
• wherein the wavelength dispersion providing means includes a first dispersion compensator for providing the optical signal wavelength dispersion sufficient to reduce the nonlinear effect, and
• the wavelength dispersion compensating means includes a second dispersion compensator having a dispersion value opposite in sign to the dispersion value of the first dispersion compensator.

An optical transmission system comprising:

• an optical transmitter for generating an optical signal;
• an optical transmission line for transmitting the optical signal generated by the optical transmitter;
• an optical receiver for recognizing the optical signal transmitted over the optical transmission line;
• nonlinear effect reducing means for smoothing variations of the strength of the optical signal transmitted through the optical transmission line,
• the nonlinear effect reducing means including means for providing optical signal wavelength dispersion sufficient to reduce a nonlinear effect;
• and
• means for compensating for the wavelength dispersion caused by the wavelength dispersion providing means,
• optical signal characteristic adjusting means for adjusting a characteristic value of the optical signal and thereby optimizing the quality of the optical signal recognized by the optical receiver.