Abstract: An apparatus comprising a carrier comprising at least one heat-generating component and a thermoelectric cooler (TEC) coupled to a surface of the carrier, wherein the cross-sectional area of the TEC is less than the cross-sectional area of the carrier, and wherein the TEC is aligned with the heat-generating component. Included is an apparatus comprising a carrier comprising a plurality of optical transmitters and an active component, at least one TEC coupled to the surface of the carrier, and a support post coupled to the surface of the carrier, wherein the support post has a higher thermal resistivity than the TEC, wherein the cross-sectional area of the TEC is less than the cross-sectional area of the carrier, and wherein the TEC is aligned with the optical transmitters, the active component, or both.

Abstract: This present disclosure provides an optical transmission method and system. The system includes a pre-coder for pre-coding an input signal into a first pre-coded signal, an encoder/separator coupled to the first pre-coded signal and arranged to encode the first and second pre-coded signals into a first encoded signal with 0 degree phase shift and a second encoded signal with 180 degree phase shift, and an optical modulator for providing optical modulation to the first and second encoded signals with a light source such that the intensity of an output optical duo-binary (ODB) signal with frequency chirp has identical logic sequence as the input signal.

Abstract: An apparatus comprising an analog-to-digital converter (ADC); a frequency-domain equalizer (FDEQ); a time-domain interpolator positioned between the ADC and the FDEQ, wherein the time domain interpolator is coupled to the ADC and the FDEQ and configured to perform a time-domain interpolation to compensate a signal sample for a plurality of ADC induced changes.

Abstract: An integrated DWDM transmitter apparatus includes a support component and a silica-on-silicon substrate overlying the support component. The support component includes a temperature adjustment component. The silica-on-silicon substrate overlies the support component and includes a silica layer and a silicon layer. The silica-on-silicon substrate includes a corresponding a substrate surface which includes a first surface region and a second surface region. In an embodiment, the two surface regions are not coplanar. The transmitter apparatus includes an optical multiplexer within the silica layer, the optical multiplexer including a plurality of input waveguides and at least an output waveguide. The transmitter apparatus also includes one or more semiconductor laser array chips overlying the first surface region of the silica-on-silicon substrate. Each of the laser array chips including two or more lasers, which are optically coupled to corresponding ones of the plurality of input waveguides.

Abstract: An integrated DWDM transmitter apparatus includes a silica-on-silicon substrate overlying a first support component. The silica-on-silicon substrate includes a silica layer overlying a silicon layer. A coefficient of thermal expansion of the first support component is substantially matched to a coefficient of thermal expansion of the silicon layer. An optical multiplexer is located within the silica layer and includes a plurality of input waveguides and at least an output waveguide. Additionally, the apparatus includes a second support component attached to a side surface of the first support component. One or more semiconductor laser array chips overlie the second support component. A coefficient of thermal expansion of the one or more semiconductor chips is substantially matched to a coefficient of thermal expansion of the second support component.

Abstract: An integrated DWDM transmitter apparatus includes a support component and a silica-on-silicon substrate overlying the support component. The support component includes a temperature adjustment component. The silica-on-silicon substrate overlies the support component and includes a silica layer and a silicon layer. The silica-on-silicon substrate includes a corresponding a substrate surface which includes a first surface region and a second surface region. In an embodiment, the two surface regions are not coplanar. The transmitter apparatus includes an optical multiplexer within the silica layer, the optical multiplexer including a plurality of input waveguides and at least an output waveguide. The transmitter apparatus also includes one or more semiconductor laser array chips overlying the first surface region of the silica-on-silicon substrate. Each of the laser array chips including two or more lasers, which are optically coupled to corresponding ones of the plurality of input waveguides.

Abstract: An optical network transmitter comprising a fractional-bit delay module, an optical modulator coupled to the fractional-bit delay module, and a band-limiting optical filter coupled to the optical modulator. Also disclosed is a transmission system comprising a source configured to generate two complementary binary data streams, a fractional-bit delay module in communication with the source and configured to delay one of the complementary binary data streams, a modulation module in communication with the source and the fractional-bit delay module and configured to convert the undelayed complementary binary data streams and the delayed complementary binary data streams into a fractional-bit delayed optical duobinary signal, and a band-limiting node in communication with the modulation module and configured to filter and transmit the optical duobinary signal.

Abstract: A dense wavelength-division-multiplexing (DWDM) system, comprising a plurality of laser transmitters, a wavelength division multiplexer (WDM) optically coupled to the laser transmitters and to an output optical transmission media, a coupler optically coupled to the output optical transmission media, an interferometric filter optically coupled to the coupler but not directly to the output optical transmission media, and a light reflector optically coupled to the interferometric filter and not directly to the output optical transmission media.

Abstract: A network apparatus comprising an optical gain medium, a wavelength division multiplexing (WDM) filter coupled to the optical gain medium, and a Faraday Rotator Mirror (FRM) coupled to the WDM, and wherein the optical gain medium, the WDM filter, and the FRM are coupled by single mode fibers to form a self-seeded external cavity laser for a DWDM wavelength channel.

Abstract: This present disclosure provides an optical transmission method and system. The system includes a pre-coder for pre-coding an input signal into a first pre-coded signal, an encoder/separator coupled to the first pre-coded signal and arranged to encode the first and second pre-coded signals into a first encoded signal with 0 degree phase shift and a second encoded signal with 180 degree phase shift, and an optical modulator for providing optical modulation to the first and second encoded signals with a light source such that the intensity of an output optical duo-binary (ODB) signal with frequency chirp has identical logic sequence as the input signal.

Abstract: An apparatus comprising a nonlinear lookup unit (NL-LUU) configured to add a phase shift to a signal sample to compensate for pattern dependent phase distortion, and one or more first phase adjustment units coupled to NL-LUU and configured to remove from the signal sample a nonlinear phase error from the NL-LUU, wherein the signal sample corresponds to a received signal polarization component of a polarization multiplexed (PM) coherent signal in a PM coherent optical system.

Abstract: An apparatus comprising at least one processor configured to receive a wavelength-division-multiplexed (WDM) signal from a remote node, wherein the WDM signal comprises a first channel carrying a first remotely generated signal, a second channel carrying a second remotely generated signal, and a third channel, adapt the WDM signal into a composite WDM signal by: dropping the first remotely generated signal from the first channel; adding a first locally generated signal to the first channel; and adding a second locally generated signal to the third channel, and provide wavelength locking to the first locally generated signal and the second locally generated signal without providing wavelength locking to the second remotely generated signal.

Abstract: An integrated DWDM transmitter apparatus includes a silica-on-silicon substrate which includes a silica layer and a silicon layer. A plurality of input waveguides and a plurality of gratings are provided within the silica layer. Each of the plurality of gratings is coupled to a corresponding one of the input waveguides. An arrayed waveguide grating within the silica layer is coupled to the plurality of input waveguides, and at least an output waveguide within the silica layer are coupled to the arrayed waveguide grating. The transmitter also includes a plurality of lasers disposed in a recessed region of the silica-on-silicon substrate, and each of the lasers is optically coupled to a corresponding one of the plurality of input waveguides. The integrated transmitter also includes plurality of photodiodes, each of the plurality of photodiodes overlying a corresponding one of the plurality of grating.

Abstract: An optical receiver comprising a frame detector configured to receive a polarized signal comprising a first bit stream and a second bit stream, and further configured to identify a plurality of frames in the first bit stream and the second bit stream using a composite header, and a time-domain equalizer (TDEQ) configured to separate the first bit stream and the second bit stream using a portion of the composite header.

Abstract: An apparatus comprising a laser transmitter having a first side and a second side, a filter coupled to the first side, a detector coupled to the second side, and a temperature controller coupled to the laser transmitter and the detector. Also disclosed is an apparatus comprising at least one processor configured to implement a method comprising receiving a photocurrent of a backward light from a laser, determining a wavelength shift offset between a wavelength of the output light and a filter transmission peak, and adjusting a temperature of the laser to substantially reduce the wavelength shift and align the wavelength of the output light with the filter transmission peak.

Abstract: An apparatus comprising a carrier comprising at least one heat-generating component and a thermoelectric cooler (TEC) coupled to a surface of the carrier, wherein the cross-sectional area of the TEC is less than the cross-sectional area of the carrier, and wherein the TEC is aligned with the heat-generating component. Included is an apparatus comprising a carrier comprising a plurality of optical transmitters and an active component, at least one TEC coupled to the surface of the carrier, and a support post coupled to the surface of the carrier, wherein the support post has a higher thermal resistivity than the TEC, wherein the cross-sectional area of the TEC is less than the cross-sectional area of the carrier, and wherein the TEC is aligned with the optical transmitters, the active component, or both.

Abstract: An apparatus comprising a plurality of optical transmitters coupled to a fiber, a signal generator coupled to the optical transmitters and configured to provide a single pilot tone to the optical transmitters, and a processor positioned within a feedback loop between the fiber and the optical transmitters, the processor configured to adjust a wavelength for each of the optical transmitters to lock the wavelengths. An apparatus comprising at least one processor configured to implement a method comprising receiving an optical signal comprising a pilot tone, detecting an amplitude and a phase of the pilot tone, calculating a quadrature term using the amplitude and the phase, and wavelength locking the optical signal using the quadrature term.

Abstract: An apparatus comprising a plurality of laser transmitters each comprising a polarization rotator, a polarization rotator mirror coupled to the laser transmitters, and a multiplexer positioned between the laser transmitters and the polarization rotator mirror. Also included is an apparatus comprising a first rotator configured to rotate light polarization by about 45 or about ?45 degrees, a second rotator configured to rotate light polarization by about 45 or about ?45 degrees, a mirror coupled to one side of the second rotator and configured to reflect at least a portion of the light, and a wavelength division multiplexing (WDM) filter positioned between the first rotator and the second rotator.

Abstract: A system and method for multiple-channel line card. The system includes a first photonic integrated device configured to receive a first optical signal and output a first plurality of electrical signals for a first plurality of channels respectively. The first plurality of channels corresponds to a first plurality of wavelength ranges associated with the first optical signal. Additionally, the system includes a first clock and recovery device configured to receive the first plurality of electric signals and retime the first plurality of electric signals, and a first switch coupled to the first clock and recovery device, a first interface, and a second interface. Moreover, the system includes the first interface configured to output a second plurality of electrical signals to another system for multiple-channel line card, and the second interface configured to couple with one or more plugged first channel devices.

Abstract: An apparatus comprising a plurality of laser dice and a heat sink positioned between the laser dice and thermally coupled to the laser dice. Also included is an apparatus comprising a chip comprising a laser core, a stopper at least partially defining a groove, wherein the stopper and the groove are positioned adjacent to the chip, and a heater located between the laser core and the groove.