Abstract: An integrated post-amplifier and laser driver assembly is provided that is implemented as a single integrated circuit and includes a plurality of amplifiers or other control devices or circuits configured to implement various effects concerning data signals received and/or transmitted by a transceiver in conjunction with which the integrated post-amplifier and laser driver assembly is employed. A digital control interface is included in the integrated post-amplifier and laser driver assembly and is configured to receive a control signal from an external digital controller. A glue logic module, and associated digital to analog controllers, of the integrated post-amplifier and laser driver assembly parse the control signal and generate and transmit corresponding analog signals to one or more of the amplifiers so as to implement processing of a data signal received from the optical receiver, as well as the control of data transmission by way of a suitable transmitter.

Abstract: This disclosure concerns optoelectronic transceivers. In one example, a transceiver is implemented as an uncompensated architecture that is substantially compliant with the SFP MSA and is capable of effective operation at a data rate of about 8.5 Gb/s. The transceiver includes a TOSA, ROSA, a printed circuit board, an LDPA disposed on the printed circuit board and configured for communication with the TOSA and the ROSA. Finally, the transceiver includes SFP compliant optical and electrical connections.

Abstract: A small form factor transceiver module that incorporates an externally modulated laser (EML). The transceiver module has a transmitter optical subassembly with a header assembly having a base with a platform extending through. The platform has a plurality of conductive traces extending through the platform for making connections on both sides of the base. A thermoelectric cooler (TEC) is used to dissipate heat from a laser within the header assembly. The TEC dissipates heat sufficiently to allow the EML to be used in the header assembly. In this manner, EMLs can be used in relatively small optical devices, including small form factor transceivers that comply with the XFP standard. The XFP modules with EMLs can be used for longer links than XFPs without EMLs. In addition, EMLs can be stabilized using TECs so that XFP modules can be used for DWDM-type applications.

Abstract: An optoelectronic assembly includes a circuit board having a set of signal traces, where one or more of the signal traces has a junction point that integrates a pad of a circuit element. Exemplary circuit elements include a resistor, capacitor, and an inductor. The junction point has a first width and a first thickness, and the one or more signal traces have a second width and a second thickness. The dimensions of the junction point and the dimensions of the one or more signal traces are configured such that the first width and the second width are substantially similar, and that the first thickness and the second thickness are substantially similar. In one embodiment, the first width is no greater than 125% of the second width.

Abstract: Adaptive transmission of optical signals. A dynamically adaptive optical receiver can include a receive optical subassembly (ROSA). The ROSA can include an opto-electronic transducer configured to receive an incoming optical signal from an incoming optical transmission link, circuitry for evaluating one or more properties related to the incoming optical signal, logic for comparing the one or more properties of the incoming optical signal to stored information representing threshold values, and circuitry for controlling a transmission characteristic of an outgoing optical signal based on a result of the comparison.

Abstract: This disclosure is concerned with transceiver modules. In one example, a transceiver module includes a receiver optical subassembly, as well as a transmitter optical subassembly having a header assembly and an externally modulated laser (EML). The header assembly includes a base with first and second sides, as well as a platform attached to the base and having an inside portion near the first side of the base and an outside portion near the second side of the base. The platform of the header assembly further includes a conductive pathway extending through part of the platform. The EML is supported by the platform and electrically communicates with the conductive pathway of the platform. The EML can be passively or actively cooled.

Abstract: A distributed feedback (“DFB”) laser featuring improved manufacturing yield and operational characteristics is disclosed. The present DFB laser includes a bottom confinement layer, an active region, and a top confinement layer disposed atop an n-doped substrate. A p-doped first top layer having a first index of refraction is disposed atop the top confinement layer. A grating is defined in the top surface of the first top layer, and a p-doped second top layer is overlaid on the grating. The two laser end facets are antireflectively coated. The grating is anisotropically etched to define a low kappa grating half and a high kappa grating half. Light waves produced in the active region interact with the grating and are biased toward the low kappa grating half that results in the majority of light signals passing through the end facet adjacent the low kappa grating half.

Abstract: Systems and methods for biasing an externally modulated laser. An inductorless bias T network is provided that includes a terminating resistor in series with a capacitor. The capacitor is an open circuit for a bias signal and a virtual ground for an RF signal. Thus, the RF signal is terminated by the terminating resistor without dissipating the bias signal through a ground return path of the RF signal. Using a charge pump inverter, a positive supply can be used to positively bias a laser and negatively bias the external modulator through the terminating resistor. A negative power supply is not required. A swing voltage provided by the RF signal causes the external modulator to modulate the light emitted by the laser.

Abstract: This disclosure concerns transceivers that include CDR bypass functionality. In one example, a 10 G XFP transceiver module includes integrated CDR functionality for reducing jitter. The 10 G XFP transceiver module also implements CDR bypass functionality so that the CDR can be bypassed at rate less than about 10 Gb/s, such as the Fibre Channel 8.5 Gb/s rate for example.

Abstract: A header assembly is provided that includes a base having a device side and a connector side. The header assembly further includes a platform attached to the base and positioned in a predetermined orientation with respect to the base. The device side of the base cooperates with a cap to define a hermetic chamber wherein one or more optoelectronic components, such as optical transmitters and optical receivers, are disposed. The platform includes an inside portion proximate the device side of the base and an outside portion proximate the connector side of the base, and the platform further includes at least one conductive pathway extending substantially through the platform so as to facilitate electrical communication between components disposed on the device side of the base, and circuits, devices and systems disposed on the connector side of the base.

Abstract: This disclosure is concerned with transceiver modules. In one example, a transceiver module includes a receiver optical subassembly, as well as a transmitter optical subassembly having a header assembly and an externally modulated laser (EML). The header assembly includes a base with first and second sides, as well as a platform attached to the base and having an inside portion near the first side of the base and an outside portion near the second side of the base. The platform of the header assembly further includes a conductive pathway extending through part of the platform. The EML is supported by the platform and electrically communicates with the conductive pathway of the platform. The EML can be passively or actively cooled.

Abstract: The wavelength of light emitted by a laser and modulated by a frequency response modulator is determined from the power of the emitted light and the current drawn by the modulator. From the temperature and current applied to the modulator and the optical power of the emitted light; the wavelength of the beam of light is determined as a function of a ratio of the current and power for each temperature of operation. As the wavelength of the emitted light shifts, for example as the laser ages or the laser temperature shifts, the inventive methods and devices then detect the wavelength shift and implement any necessary adjustments in the operating conditions of the laser diode. For example, a thermoelectric cooler can be used to heat or cool the laser diode as necessary to thereby adjust the wavelength of the emitted light.

Abstract: This disclosure concerns distributed feedback (“DFB”) lasers. In one example, a DFB laser includes a body that has first and second end facets. The DFB laser is implemented in a stack configuration that includes an active region interposed between a first top layer and a substrate. A second top layer is disposed on the first top layer and has an index of refraction different from that of the first top layer. Additionally, a grating is defined in one of the top layers and extends from the first end facet to the second end facet. The grating includes a tooth/gap structure whose configuration varies between the first end facet and the second end facet. Finally, an antireflective (AR) coating is disposed on the first end facet and on the second end facet.

Abstract: An interference-reducing optoelectronic device determines the value of a current data bit in an optical data stream. A receiver receives the optical data stream, which is converted to a series of samples by a D/A converter. A set of adaptive filters, each filter corresponding to a unique possible value for one or more prior data bits, filters the series of samples utilizing variable tap coefficients to generate filtered output values. The variable tap coefficients are at least partially different than the variable tap coefficients of another adaptive filter. Comparators compare the filtered output values against filter-specific adaptive threshold values to generate tentative values for the current data bit. A delay mechanism delays a determined value for the prior data bits, and a selection mechanism determines the value of the current data bit by selecting the tentative value corresponding to the delayed determined value of the prior data bits.

Abstract: This disclosure concerns a platform suitable for use in connection with optoelectronic components and devices. In one example, the platform includes multiple stacked platform layers. A conductive pathway of the platform is supported by at least one of the stacked platform layers, and the conductive pathway is configured and arranged so as to be at least partly coextensive with the platform.

Abstract: A small form factor transceiver module that incorporates an externally modulated laser (EML). The transceiver module has a transmitter optical subassembly with a header assembly having a base with a platform extending through. The platform has a plurality of conductive traces extending through the platform for making connections on both sides of the base. A thermoelectric cooler (TEC) is used to dissipate heat from a laser within the header assembly. The TEC dissipates heat sufficiently to allow the EML to be used in the header assembly. In this manner, EMLs can be used in relatively small optical devices, including small form factor transceivers that comply with the XFP standard. The XFP modules with EMLs can be used for longer links than XFPs without EMLs. In addition, EMLs can be stabilized using TECs so that XFP modules can be used for DWDM-type applications.

Abstract: A multi-layer feedthrough structure for use in optoelectronic equipment. The feedthrough structure is composed of multiple stacked ceramic layers that together form a multi-layer platform. The multi-layer platform bisects the base portion of a header assembly that is located within the transmitter optical subassembly such that an interior portion of the multi-layer platform is located within the header assembly and an exterior portion is disposed outside. Each layer contains at least a portion of a plurality of conductive pathways that extend from the exterior to the interior portion of the multi-layer platform. A top insulating layer enables the conductive pathways to pass from the exterior to the interior portion of the platform without electrically contacting the header assembly base. The conductive pathways serve as electrical interconnects between components located within the header assembly and structures outside thereof.

Abstract: A transistor header assembly for use in transmitter optical subassemblies of optical transceivers. The header assembly has a base with a platform extending through. The platform has a conductive trace extending through the platform for making connections on both sides of the base. A thermoelectric cooler (TEC) is used to dissipate heat from a laser within the header assembly. The TEC dissipates heat sufficiently to allow an externally modulated laser (EML) to be used in the header assembly. In this manner, EMLs can be used in relatively small optical devices, including small form factor transceivers that comply with the XFP standard. The XFP modules with EMLs can be used for longer links than XFPs without EMLs. In addition, EMLs can be stabilized using TECs so that XFP modules can be used for DWDM-type applications.

Abstract: An improved monitoring and control system for a laser in a header assembly of a transmitter optical subassembly (“TOSA”) is disclosed. The monitoring and control system, includes one or more monitor photodiodes (“MPDs”), is positioned together with the laser on a component submount. The submount in turn is mated with a multi-layer platform (“MLP”) that forms part of the header assembly. The MLP hermetically extends through the header assembly to provide a plurality of electrical interconnects for the laser, MPD(s), and other submount components. In one embodiment, a single MPD is located proximate the laser to receive back facet laser light emission. Measurement of the back facet emission enables the MPD to determine laser intensity. In another embodiment, two MPDs are joined together to receive the back facet laser light emission. Comparison of each MPD's measurement enables the laser's wavelength to be determined and adjusted to optimize its performance.

Abstract: A header assembly is provided that includes a base having a device side and a connector side. The header assembly further includes a platform attached to the base and positioned in a predetermined orientation with respect to the base. The device side of the base cooperates with a cap to define a hermetic chamber wherein one or more optoelectronic components, such as optical transmitters and optical receivers, are disposed. The platform includes an inside portion proximate the device side of the base and an outside portion proximate the connector side of the base, and the platform further includes at least one conductive pathway extending substantially through the platform so as to facilitate electrical communication between components disposed on the device side of the base, and circuits, devices and systems disposed on the connector side of the base.