Abstract: A method may include transmitting, by an optical device, a first channel. The first channel may have a first set of subcarriers. The first channel may be attenuated during transmission by a filter associated with a wavelength selective switch. The method may further include transmitting, by the optical device, a second channel. The second channel may have a second set of subcarriers. The second channel may be attenuated during transmission by the filter associated with the wavelength selective switch. The first channel and the second channel being included in a super-channel. The first set of subcarriers may be selected based on a first signal quality factor associated with attenuation of the first set of subcarriers by the filter. The second set of subcarriers may be selected based on a second signal quality factor associated with attenuation of the second set of subcarriers by the filter.

Abstract: An apparatus may include a plurality of wavelength selective switches (WSSs). The apparatus may include a plurality of transmitters. The transmitters may transmit a plurality of super-channels. The apparatus may include a plurality of passive power splitters corresponding to the plurality of transmitters. The plurality of passive power splitters may receive the plurality of super-channels. The plurality of passive power splitters may generate a respective set of power-split super-channels for each super-channel of the plurality of super-channels. The plurality of passive power splitters may transmit each power-split super-channel of the respective set of power-split super-channels to a corresponding WSS of the plurality of WSSs. A WSS, of the plurality of WSSs, may receive a plurality of power-split super-channels, of the respective sets of power-split super-channels, from the plurality of passive power splitters.

Abstract: A method may include transmitting, by an optical device, a first set of channels using a first modulation format. The first set of channels may be attenuated during transmission by a filter associated with a wavelength selective switch. The method may further include transmitting, by the optical device, a second set of channels using a second modulation format. The second set of channels may be attenuated during transmission by the filter associated with the wavelength selective switch. The first set of channels and the second set of channels may be included in a super-channel. The first modulation format may be selected based on a first signal quality factor associated with attenuation by the filter associated with the wavelength selective switch. The second modulation format may be selected based on a second signal quality factor associated with attenuation by the filter associated with the wavelength selective switch.

Abstract: A method may include transmitting, by an optical device, a first set of channels at a first transmission power. The first set of channels may be attenuated during transmission by a filter associated with a wavelength selective switch. The method may further include transmitting, by the optical device, a second set of channels at a second transmission power. The second set of channels may be attenuated during transmission by the filter associated with the wavelength selective switch. The first set of channels and the second set of channels may be included in a super-channel. The first transmission power may be selected based on a first signal quality factor resulting from attenuation, by the filter, of the first set of channels. The second transmission power may be selected based on a second signal quality factor resulting from attenuation, by the filter, of the second set of channels.

Abstract: A method may include interleaving, by an optical device, a set of bits of a first channel with a set of bits of a second channel. The first channel may include first forward error correction (FEC) data associated with the set of bits of the first channel and the second channel may include second FEC data associated with the set of bits of the second channel. The method may further include transmitting first information via the first channel and second information via the second channel. The first information may include a portion of the set of bits of the first channel, a portion of the set of bits of the second channel, and the first FEC data. The second information may include another portion of the set of bits of the first channel, another portion of the set of bits of the second channel, and the second FEC data.

Abstract: A method may include transmitting, by an optical device, a first set of channels using a first baud rate. The first set of channels may be attenuated during transmission by a filter associated with a wavelength selective switch. Transmitting, by the optical device, a second set of channels using a second baud rate. The second set of channels may be attenuated during transmission by the filter associated with the wavelength selective switch. The first set of channels and the second set of channels may be included in a super-channel. The first baud rate may be selected based on a first signal quality factor associated with attenuation by the filter associated with the wavelength selective switch. The second baud rate may be selected based on a second signal quality factor associated with attenuation by the filter associated with the wavelength selective switch.

Abstract: An optical transmitter may include one or more lasers configured to provide a primary optical signal having a primary wavelength and a secondary optical signal having a secondary wavelength to a modulator via corresponding first and second modulator inputs. The modulator may combine the primary and secondary optical signals into a combined optical signal and modulate, with an electrical signal, the combined optical signal to provide a modulated optical signal to an optical filter. The optical filter may be configured to separate, from the modulated optical signal, a modulated primary optical signal having the primary wavelength and a modulated secondary optical signal having the secondary wavelength and provide the modulated primary optical signal to a primary optical link and the modulated secondary optical signal to a secondary optical link.

Abstract: A Raman pump may include a dual output laser configured to output two optical signals; a delay interferometer configured to delay a first of the two optical signals to decorrelate the two optical signals from each other; and a combiner configured to combine the delayed first of the two optical signals and a second of the two optical signals to provide a Raman amplification signal.

Abstract: Consistent with the present disclosure, optical filters are provided in a reconfigurable optical add-drop multiplexer (ROADM). In one example, groups of optical signals are amplified by corresponding erbium-doped fiber amplifiers (EDFAs) and supplied to each optical filter, which has a passband that includes the wavelengths associated with the received optical signal group. Light at wavelengths outside the passband of each optical filter, such as amplified stimulated emission (ASE) light generated by a respective EDFA, is significantly attenuated. Each optical signal group, after such amplification and filtering may then be switched and combined in a multicast switch before being directed toward a desired optical communication path. When, for example, first and second optical signal groups are combined, however, the first optical signal group is accompanied by little or no ASE light at the second optical signal group wavelengths.

Abstract: Consistent with the present disclosure, optical filters are provided in a reconfigurable optical add-drop multiplexer (ROADM). In one example, groups of optical signals are amplified by corresponding erbium-doped fiber amplifiers (EDFAs) and supplied to each optical filter, which has a passband that includes the wavelengths associated with the received optical signal group. Light at wavelengths outside the passband of each optical filter, such as amplified stimulated emission (ASE) light generated by a respective EDFA, is significantly attenuated. Each optical signal group, after such amplification and filtering may then be switched and combined in a multicast switch before being directed toward a desired optical communication path. When, for example, first and second optical signal groups are combined, however, the first optical signal group is accompanied by little or no ASE light at the second optical signal group wavelengths.

Abstract: A semiconductor optical amplifier module may include a beam splitter to split an optical signal into two polarization optical signals including a first polarization optical signal with a Transverse Magnetic (TM) polarization provided along a first path of two paths, and a second polarization optical signal with a Transverse Electric (TE) polarization provided along a second path of the two paths; a first rotator to rotate the TM polarization of the first polarization optical signal to TE polarization; a first semiconductor optical amplifier to amplify the rotated first polarization optical signal to output a first resultant optical signal; a second semiconductor optical amplifier to amplify the second polarization optical signal; and a second rotator to rotate the polarization of the amplified second polarization optical signal to output a second resultant optical signal; and a beam combiner to combine the first resultant optical signal and the second resultant optical signal.

Abstract: Optical autodiscovery is provide between two optical modules to insure that when an optical signal is coupled between the two optical module, the optical signal from a first module does not interfere with operation of a second module. The autodiscovery is implemented by sending an optical identification signal from the first optical module via the coupling to the second optical module from which signal, the second optical module can verify and determined acceptance of the coupled first optical module. During this autodiscovery process, the optical identification signal from the first optical module may be attenuated or shifted in optical spectrum so as not to interfere with the operation of the second optical module. Autodiscovery may also be employed in cases where a first optical module is to receive an optical signal from a second module.

Abstract: A number of carriers are selected according to a modulation format and symbol rate to realize a superchannel having fixed capacity, for example. At a receive node, the superchannel is optically demultiplexed from a plurality of other superchannels. The plurality of carriers are then supplied to a photodetector circuit, which receives additional light at one of the optical signal carrier wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of the carriers is unnecessary.

Abstract: Consistent with the present disclosure, a wavelength division multiplexed (WDM) optical communication system including on-off-keying (OOK) transmitters, for example, may be upgraded to include advanced modulation format transmitters, such as quadrature phase shift keying (QPSK) transmitters. Rather than replace all the OOK transmitters with QPSK transmitters at once, each OOK transmitter is replaced with a lower rate modulation format transmitter, such as a binary phase shift keying (BPSK) transmitter, as capacity needs increase. The BPSK transmitters supply (BPSK) optical signals that are more tolerant of noise caused by cross phase modulation (XPM) induced by OOK signals. Accordingly, such BPSK optical signals have fewer associated data detection errors in the receiver. Moreover, BPSK modulated optical signals induce little XPM-related noise in co-propagating QPSK modulated optical signals.

Abstract: A Raman pump may include a dual output laser configured to output two optical signals; a delay interferometer configured to delay a first of the two optical signals to decorrelate the two optical signals from each other; and a combiner configured to combine the delayed first of the two optical signals and a second of the two optical signals to provide a Raman amplification signal.

Abstract: A semiconductor optical amplifier module may include a beam splitter to split an optical signal into two polarization optical signals including a first polarization optical signal with a Transverse Magnetic (TM) polarization provided along a first path of two paths, and a second polarization optical signal with a Transverse Electric (TE) polarization provided along a second path of the two paths; a first rotator to rotate the TM polarization of the first polarization optical signal to TE polarization; a first semiconductor optical amplifier to amplify the rotated first polarization optical signal to output a first resultant optical signal; a second semiconductor optical amplifier to amplify the second polarization optical signal; and a second rotator to rotate the polarization of the amplified second polarization optical signal to output a second resultant optical signal; and a beam combiner to combine the first resultant optical signal and the second resultant optical signal.

Abstract: Consistent with the present disclosure optical interleaver and deinterleaver circuits are integrated onto a substrate. The inputs to the interleaver and the outputs of the deinterleaver are each coupled to a corresponding variable optical attenuator (VOA) and optical tap, which are also provided on the substrate. The optical taps supply a portion of the output of each VOA to a corresponding photodetector. A control circuit, which is coupled to the photodetector, in turn, supplies a control signal to each VOA based on the output of the photodetector. Accordingly, optical multiplexing and demultiplexing components, as well as monitoring and power regulating components are provided on the same chip. Such a chip may be compact, relatively inexpensive, and has reduced power consumption compared to optical multiplexer and demultiplexer equipment including discrete components.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data forming a plurality of corresponding carriers. The plurality of carriers are then optically combined with a fixed spacing combiner to form a superchannel of a fixed capacity. Accordingly, the number of carriers are selected according to a modulation format and symbol rate to realize the fixed capacity, for example. The superchannel is then transmitted over an optical communication path to a receive node. At the receive node, the superchannel is optically demultiplexed from a plurality of other superchannels.

Abstract: Consistent with the present disclosure, a wavelength division multiplexed (WDM) optical communication system including on-off-keying (OOK) transmitters, for example, may be upgraded to include advanced modulation format transmitters, such as quadrature phase shift keying (QPSK) transmitters. Rather than replace all the OOK transmitters with QPSK transmitters at once, each OOK transmitter is replaced with a lower rate modulation format transmitter, such as a binary phase shift keying (BPSK) transmitter, as capacity needs increase. The BPSK transmitters supply (BPSK) optical signals that are more tolerant of noise caused by cross phase modulation (XPM) induced by OOK signals. Accordingly, such BPSK optical signals have fewer associated data detection errors in the receiver. Moreover, BPSK modulated optical signals induce little XPM-related noise in co-propagating QPSK modulated optical signals.