Abstract: A method includes modulating a laser that is coupled to a fiber; modulating the laser with a member selected from the group consisting of low frequency thermal modulation or bias modulation to broaden a laser linewidth, increase an SBS threshold and reduce an IIN; and modulating the laser with a predistorting modulation selected from the group consisting of phase modulation or amplitude modulation, the predistorting modulation being of equal magnitude but opposite phase as that produced in at least one member selected from the group consisting of the laser or the fiber as a result of the low frequency thermal modulation or bias modulation.

Abstract: Synchronizing SBS suppressing optical phase/frequency modulation of each of a plurality of optical transmitters can be achieved with a plurality of optical transmitters conveying a plurality of optical carriers; and a synchronizer coupled to each of the plurality of optical transmitters to synchronize the SBS suppressing optical phase/frequency modulation of each of the plurality of optical carriers.

Abstract: Synchronizing SBS suppressing optical phase/frequency modulation of each of a plurality of optical transmitters can be achieved with a plurality of optical transmitters conveying a plurality of optical carriers; and a synchronizer coupled to each of the plurality of optical transmitters to synchronize the SBS suppressing optical phase/frequency modulation of each of the plurality of optical carriers.

Abstract: A modulated optical system with cross-modulation compensation reduces or corrects cross-modulation that might occur in a multichannel RF signal modulating a laser. The system detects the cross-modulation, for example, by detecting an envelope of the RF signal or by detecting RF power fluctuations, generates a cross-modulation detection signal, and imparts a compensating cross-modulation by adjusting a bias current of the laser in response to the cross-modulation detection signal.

Abstract: A method includes reading operation parameters from a non-volatile memory located in a pluggable module that is coupled to a host module; processing the operational parameters with a processor located in the host module to control operation of a predistortion circuit located in the host module; adding predistortion to a signal with the predistortion circuit located in the host module and then sending the predistorted signal to the pluggable module. An apparatus includes a host module including a predistortion circuit and a processor coupled to the predistortion circuit; and a pluggable module coupled to the host module, wherein the pluggable module includes a non-volatile memory containing operational parameters for the predistortion circuit of the host module, wherein the operational parameters are processed by the processor of the host module to control the predistortion circuit of the host module.

Abstract: A distortion compensation circuit compensates for distortion generated by one or more non-linear elements such as a laser device and may include a primary signal path for carrying an input signal and one or more secondary signal paths for generating distortion. The distortion compensation circuit may also include one or more controllable phase inverters on at least one of the paths. For example, the secondary signal path may include a distortion generator to produce distortion products from the input signal and a signal controlled phase inverter that inverts the phase of the distortion products. The distortion generator and phase inverter may be combined as an invertible distortion generator. The phase inversion may be controlled in response to a phase inversion control signal generated based on one or more parameters such as temperature.

Abstract: A method includes reading operation parameters from a non-volatile memory located in a pluggable module that is coupled to a host module; processing the operational parameters with a processor located in the host module to control operation of a predistortion circuit located in the host module; adding predistortion to a signal with the predistortion circuit located in the host module and then sending the predistorted signal to the pluggable module. An apparatus includes a host module including a predistortion circuit and a processor coupled to the predistortion circuit; and a pluggable module coupled to the host module, wherein the pluggable module includes a non-volatile memory containing operational parameters for the predistortion circuit of the host module, wherein the operational parameters are processed by the processor of the host module to control the predistortion circuit of the host module.

Abstract: A method includes tapping power from a broadband RF input, filtering the tapped power with a plurality of band pass filters, measuring the power filtered by each of the plurality of band pass filters and controlling an adaptive equalizer circuit to flatten excessive non-linear frequency response from the broadband RF input as a function of measured power filtered at each of the plurality of band pass filters.

Abstract: A method includes hosting a plurality of transmitter modules with a host module, where the host module includes common circuitry shared by the plurality of pluggable transmitter modules. An apparatus includes a host module; and a plurality of transmitter modules coupled to the host module, where the host module includes common circuitry shared by the plurality of pluggable transmitter modules.

Abstract: A method includes connecting a first end of an optoelectronic device with an electrical back plate including blind mating; and connecting a second end of the optoelectronic device with an optical back plate including blind mating. An apparatus includes an optoelectronic device including a first end having an electrical interface for blind mating and a second end having an optical interface for blind mating.

Abstract: A method includes tuning a host module to a reference module standard; and adjusting each of a plurality of pluggable optical modules coupled to the host module to mimic the reference module standard for a set of load conditions. An apparatus includes a host module tuned to a reference module standard; and a plurality of pluggable optical modules coupled to the host module, wherein each of the plurality of pluggable optical modules mimics the reference standard for a specific set of load conditions.

Abstract: A distortion compensation circuit compensates for distortion generated by one or more non-linear elements such as a laser device and may include a primary signal path for carrying an input signal and one or more secondary signal paths for generating distortion. The distortion compensation circuit may also include one or more controllable phase inverters on at least one of the paths. For example, the secondary signal path may include a distortion generator to produce distortion products from the input signal and a signal controlled phase inverter that inverts the phase of the distortion products. The distortion generator and phase inverter may be combined as an invertible distortion generator. The phase inversion may be controlled in response to a phase inversion control signal generated based on one or more parameters such as temperature.

Abstract: A modulated optical system with anti-clipping reduces or corrects clipping that might occur in the laser as a result of negative spikes or peaks in a multichannel RF signal. The system generally detects an envelope of the RF signal to generate an anti-clipping signal that follows at least a portion of the envelope and prevents one or more negative peaks from causing clipping by adjusting a bias current in response to the anti-clipping signal. The system may also reduce cross modulation by clamping the anti-clipping signal at an anti-clipping limit during lower power periods of the RF signal.

Abstract: A distortion compensation circuit compensates for distortion generated by one or more non-linear elements such as a laser device. The distortion compensation circuit may be used in an optical transmitter, such as a laser transmitter used for forward path CATV applications. The distortion compensation circuit may include a primary signal path and a secondary signal path that receive an input signal. The secondary signal path produces distortion of a magnitude corresponding to the magnitude of, but at an opposite phase to, the distortion generated by the non-linear amplifier. The secondary signal path includes a plurality of distortion sub-paths with each of the distortion sub-paths configured to produce intermodulation distortion products of the same distortion order but for different frequency dependent orders in a time dependent series representative of the distortion produced by the non-linear amplifier.

Abstract: A distortion compensation circuit compensates for distortion generated by one or more non-linear elements such as a laser device and may include a primary signal path for carrying an input signal and one or more secondary signal paths for generating distortion. The distortion compensation circuit may also include one or more controllable phase inverters on at least one of the paths. For example, the secondary signal path may include a distortion generator to produce distortion products from the input signal and a signal controlled phase inverter that inverts the phase of the distortion products. The distortion generator and phase inverter may be combined as an invertible distortion generator. The phase inversion may be controlled in response to a phase inversion control signal generated based on one or more parameters such as temperature. The secondary signal path may also include separate distortion sub-paths to produce frequency independent distortion products and frequency dependent distortion products.

Abstract: A method includes driving a multi-section laser, wherein each section is electrically isolated from an adjacent section with sufficient resistance so that current through each section is contained substantially in that section. An apparatus includes a multi-section laser, wherein each section is electrically isolated from an adjacent section with sufficient resistance so that current through each section is contained substantially in that section.

Abstract: A method includes modulating a laser that is coupled to a fiber; modulating the laser with a member selected from the group consisting of low frequency thermal modulation or bias modulation to broaden a laser linewidth, increase an SBS threshold and reduce an IIN; and modulating the laser with a predistorting modulation selected from the group consisting of phase modulation or amplitude modulation, the predistorting modulation being of equal magnitude but opposite phase as that produced in at least one member selected from the group consisting of the laser or the fiber as a result of the low frequency thermal modulation or bias modulation.

Abstract: A predistortion circuit provides a predistorted input signal that compensates for distortion generated by a non-linear amplifier such as a laser device. The predistortion circuit may be used in an optical transmitter designed for broadband applications, such as a laser transmitter used for forward path CATV applications. The predistortion circuit may include a primary signal path and a secondary signal path that receive an input signal. A second order distortion generator on the secondary signal path generates predistortion of a magnitude corresponding to the magnitude of, but at an opposite phase to, the distortion generated by the non-linear amplifier. The second order distortion generator includes diodes with an adjustable diode bias to control phase, magnitude and/or magnitude/phase versus frequency of the predistortion.

Abstract: A modulated optical system with cross-modulation compensation reduces or corrects cross-modulation that might occur in a multichannel RF signal modulating a laser. The system detects the cross-modulation, for example, by detecting an envelope of the RF signal or by detecting RF power fluctuations, generates a cross-modulation detection signal, and imparts a compensating cross-modulation by adjusting a bias current of the laser in response to the cross-modulation detection signal.

Abstract: A modulated optical system with anti-clipping reduces or corrects clipping that might occur in the laser as a result of negative spikes or peaks in a multichannel RF signal. The system generally detects an envelope of the RF signal to generate an anti-clipping signal that follows at least a portion of the envelope and prevents one or more negative peaks from causing clipping by adjusting a bias current in response to the anti-clipping signal. The system may also reduce cross modulation by clamping the anti-clipping signal at an anti-clipping limit during lower power periods of the RF signal.