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.

Abstract: An apparatus comprising a plurality of optical transmitters and a wavelength locker shared by the plurality of optical transmitters. A periodic transmission filter used for wavelength locker operations is in a network communication path and shapes optical transmissions from the plurality of optical transmitters to a network. An apparatus comprising at least one processor configured to receive a pre-filter signal corresponding to part of an optical signal comprising a pilot tone and to receive a post-filter signal corresponding to a part of the optical signal that passes through a period transmission filter, wherein a filtered part of the optical signal is directed into a network. The processor is also configured to perform wavelength locking based on a quadrature detection technique that aligns an adiabatic logical one position of a modulated transmission signal with a spectral transmission peak of the period transmission filter.

Abstract: A BOSA package comprising only one cylindrical TO package comprising a ROSA and a TOSA, and an optical port in optical communication with the ROSA and the TOSA. Also disclosed is a TO package comprising a TOSA for transmitting a first optical signal, a ROSA for receiving a second optical signal, an optical communication window, and a TFF positioned such that the first optical signal transmitted from the TOSA is reflected by the TFF toward the optical communication window and the second optical signal received from the optical communication window passes through the TFF and to the ROSA.

Abstract: Method and system for band blocking in an optical telecommunication network. According to an embodiment, the present invention provides a system for optical network. The system includes an input that is configured to receive an input signal through a first optical input. The system also includes a band splitting module that is coupled to the input. The band splitting module is configured to separate the input signal into a plurality of bands. The plurality of bands includes a first band and a second band. The first band includes a first plurality of wave channels. The first plurality of wave channels is characterized by a first channel spacing. The second band includes a second plurality of wave channels, which is characterized by a second channel spacing.

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: 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: An optical apparatus, comprising a polarization beam splitter (PBS) comprising a birefringent crystal having a front-end and a back-end, and an optical rotator positioned on the back-end of the birefringent crystal. Included is an optical apparatus comprising a PBS comprising a birefringent crystal and an optical rotator, wherein the PBS is configured to receive a multiplexed optical signal comprising a first polarized optical signal and a second polarized optical signal, wherein the second polarized optical signal is orthogonal to the first polarized optical signal, separate the first polarized optical signal from the second polarized optical signal using the birefringent crystal, and rotate the second polarized optical signal using the optical rotator such that the rotated second polarized optical signal is parallel to the first polarized optical signal. The PBS may further comprise only one lens, wherein the lens is positioned on the front-end of the birefringent crystal.

Abstract: A method comprising coupling a circuit to an opto-electronic package via an anisotropic conductive film (ACF), wherein the opto-electronic package is configured to communicate electrical signals via the coupling at a maximum frequency of about 10 gigahertz (GHz) to about 40 GHz. An apparatus comprising, an opto-electronic package comprising a plurality of first electrodes, and a circuit comprising a plurality of second electrodes, wherein at least one of the first electrodes is coupled to at least one of the second electrodes via an ACF, and wherein the opto-electronic package is configured to communicate electrical signals via the coupling at a maximum frequency of about 10 GHz to about 40 GHz.

Abstract: An apparatus and method for performing joint equalization and timing recovery in coherent optical systems. The method includes equalizing signals to generate compensated polarization signals, wherein timing error in a distorted optical signal is calculated based on one of the compensated polarization signals. The method further includes performing resampling polarization signals to correct timing offset in an optical signal based on the calculated timing error. The calculated timing error may also be used to adaptively control one or more operating parameters of an external device.

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 optical receiver comprising a frontend configured to receive an optical signal and convert the optical signal into a plurality of digital electrical signals comprising a plurality of spectrally shaped subcarrier signals carrying symbol mapped data information, and a digital signal processor (DSP) unit coupled to the frontend and configured to receive the digital signals from the frontend, demulitplex the digital signals into the subcarrier signals, and compensate chromatic dispersion (CD) for each of the subcarrier signals by applying an equalizer, wherein each of the subcarrier signals is associated with a unique tone frequency and a unique spectral shape. Also disclosed is an optical transmitter comprising a digital signal processor (DSP) unit configured to map data symbols onto a plurality of electrical subcarrier signals that are non-overlapping and spectrally shaped in a frequency domain.

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: 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: 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 and method for performing joint equalization and timing recovery in coherent optical systems. The method includes equalizing signals to generate compensated polarization signals, wherein timing error in a distorted optical signal is calculated based on one of the compensated polarization signals. The method further includes performing resampling polarization signals to correct timing offset in an optical signal based on the calculated timing error. The calculated timing error may also be used to adaptively control one or more operating parameters of an external device.

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: Included is an apparatus comprising a first circuit component comprising a plurality of optical devices each having an optical input port and an optical output port. All of the optical input ports and all of the optical output ports are positioned on a first side of the circuit component. Also included is a circuit component comprising a plurality of optical devices. The circuit component further comprises a plurality of electrical inputs coupled to the optical devices and positioned on a first side of the circuit component. The circuit component also comprises a plurality of optical input ports coupled to the optical devices and positioned on a second side of the circuit component that does not share any edges with the first side.

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: An apparatus comprising a plurality of optical transmitters and a wavelength locker shared by the plurality of optical transmitters. A periodic transmission filter used for wavelength locker operations is in a network communication path and shapes optical transmissions from the plurality of optical transmitters to a network. An apparatus comprising at least one processor configured to receive a pre-filter signal corresponding to part of an optical signal comprising a pilot tone and to receive a post-filter signal corresponding to a part of the optical signal that passes through a period transmission filter, wherein a filtered part of the optical signal is directed into a network. The processor is also configured to perform wavelength locking based on a quadrature detection technique that aligns an adiabatic logical one position of a modulated transmission signal with a spectral transmission peak of the period transmission filter.

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.