Abstract: A transmitter block, comprising an optical source, a modulator, a transmission circuit and a control circuit. The optical source has a laser providing an optical signal. The modulator is configured to encode data into the optical signal using an m-quadrature amplitude modulation format. The transmission circuit has circuitry to receive data to be encoded into the optical signal. The transmission circuit has at least one drive circuit supplying driver signals to the modulator to cause the modulator to encode data into the optical signal using the m-quadrature amplitude modulation format. The control circuit supplies control signals to the transmission circuit to cause the transmission circuit to change the m-quadrature amplitude modulation format from a first m-quadrature amplitude modulation format to a second m-quadrature amplitude modulation format based upon predicted degradation of a link to receive modulated data from the modulator.

Abstract: An apparatus comprising a control circuit providing a variable control signal, and a transmitter. The transmitter operable to provide a modulated optical signal including a plurality of optical subcarriers. One of the plurality of optical subcarriers carries a sequence of modulation symbols. The sequence of modulation symbols includes modulation symbols that are output with a variable transmission frequency in accordance with a transmission probability distribution that is variable based on the control signal.

Abstract: A control circuit, comprising a processor, and a computer readable medium is described. The computer readable medium stores logic that causes the processor to analyze performance data of a link carrying data encoded in a first modulation format with a degradation prediction algorithm to determine a predicted level of degradation of the link. The processor provides first control signals to a transmitter block, and second control signals to a receiver block based upon the predicted level of degradation of the link over time. The first control signals cause the transmitter block to encode data to be transmitted over the link in a second modulation format. The second control signals cause the receiver block to decode data received from the link using the second modulation format. The first and second modulation formats conform to requirements of a same m-quadrature amplitude modulation protocol.

Abstract: Described herein is an apparatus including a continuous wave idler and an optical coupler that provide an optical signal having a power greater than optical channels carrying data, and positioned at a cross-over point between two spectral bands, with each band encompassing multiple optical channels.

Abstract: Described herein is an apparatus including a continuous wave idler and an optical coupler that provide an optical signal having a power greater than optical channels carrying data, and positioned at a cross-over point between two spectral bands, with each band encompassing multiple optical channels.

Abstract: A control circuit, comprising a processor, and a computer readable medium is described. The computer readable medium stores logic that causes the processor to analyze performance data of a link carrying data encoded in a first modulation format with a degradation prediction algorithm to determine a predicted level of degradation of the link. The processor provides first control signals to a transmitter block, and second control signals to a receiver block based upon the predicted level of degradation of the link over time. The first control signals cause the transmitter block to encode data to be transmitted over the link in a second modulation format. The second control signals cause the receiver block to decode data received from the link using the second modulation format. The first and second modulation formats conform to requirements of a same m-quadrature amplitude modulation protocol.

Abstract: An apparatus comprising a control circuit providing a variable control signal, and a transmitter. The transmitter operable to provide a modulated optical signal including a plurality of optical subcarriers. One of the plurality of optical subcarriers carries a sequence of modulation symbols. The sequence of modulation symbols includes modulation symbols that are output with a variable transmission frequency in accordance with a transmission probability distribution that is variable based on the control signal.

Abstract: A transmitter block, comprising an optical source, a modulator, a transmission circuit and a control circuit. The optical source has a laser providing an optical signal. The modulator is configured to encode data into the optical signal using an m-quadrature amplitude modulation format. The transmission circuit has circuitry to receive data to be encoded into the optical signal. The transmission circuit has at least one drive circuit supplying driver signals to the modulator to cause the modulator to encode data into the optical signal using the m-quadrature amplitude modulation format. The control circuit supplies control signals to the transmission circuit to cause the transmission circuit to change the m-quadrature amplitude modulation format from a first m-quadrature amplitude modulation format to a second m-quadrature amplitude modulation format based upon predicted degradation of a link to receive modulated data from the modulator.

Abstract: Fiber optic transmission technologies that allow DPSK or even higher order PSK to be performed at 20 gigabits per second per channel or even higher bit rates in a WDM (e.g., DWDM) wavelength multiplexed channeling environment. The technology employs pre-compensation of chromatic error dispersion such for each of most, if not all, channels have a portion of minimum absolute accumulated dispersion that occurs somewhere within the length (perhaps at the mid-point) of the optical channel. Post-compensation is then employed at the receiver to reduce or even potentially eliminate the chromatic dispersion. The technology allows for reduced bit error rates at high bit rates over even very long haul (e.g., trans-oceanic submarine or long terrestrial) optical fiber links, and for all channels.

Abstract: Fiber optic transmission technologies that allow DPSK or even higher order PSK to be performed at 20 gigabits per second per channel or even higher bit rates in a WDM (e.g., DWDM) wavelength multiplexed channeling environment. The technology employs pre-compensation of chromatic error dispersion such for each of most, if not all, channels have a portion of minimum absolute accumulated dispersion that occurs somewhere within the length (perhaps at the mid-point) of the optical channel. Post-compensation is then employed at the receiver to reduce or even potentially eliminate the chromatic dispersion. The technology allows for reduced bit error rates at high bit rates over even very long haul (e.g., trans-oceanic submarine or long terrestrial) optical fiber links, and for all channels.