Abstract: A coaxial transmitter optical subassembly (TOSA) including a side-by-side laser diode and monitor photodiode package, consistent with embodiments of the present disclosure, may be used in an optical transceiver for transmitting an optical signal at a channel wavelength. In an embodiment, the coaxial TOSA includes a laser sub-mount coupled to a mounting region defined by a body of the coaxial TOSA. The laser sub-mount includes a monitor photodiode disposed adjacent to a side of a laser diode such that a sensor region of the monitor photodiode is disposed within, or in close proximity to, a light cone emitted by a light emitting surface of the laser diode. The monitor photodiode is thus configured to directly receive a portion of emitted channel wavelengths from the laser diode for monitoring purposes.

Abstract: The present disclosure provides a multi-channel parallel optical receiving device, including a carrier, a light receiving chip, a plurality of optoelectronic diodes disposed on a top surface of an end of the carrier, an optical fiber connector disposed in another end of the carrier, and an arrayed waveguide grating disposed on the top surface of the carrier. The plurality of optoelectronic diodes is electrically connected to the light receiving chip, and an input end of the arrayed waveguide grating is connected to the optical fiber connector for receiving an optical signal from the optical fiber. The optical signals are divided into multi-channel optical signals in parallel. The top surface of an output end of the arrayed waveguide grating is at a predetermined angle, causing the multi-channel optical signals to be reflected by the top surface and to photosensitive surfaces of the optoelectronic diodes arranged in parallel.

Abstract: The present disclosure is generally directed to a transmitter optical subassembly (TOSA) having a hermetically-sealed housing with a feedthrough device that electrically isolates RF and power traces. In more detail, a TOSA consistent with the present disclosure includes a substrate with driving circuitry disposed thereon. A first end of the substrate may electrically couple to transmit connecting circuitry and a second end may couple to a hermetically-sealed housing. The hermetically-sealed housing can include one or more laser packages for emitting associated channel wavelengths in addition to monitor photodiodes (PDs), and temperature control devices such as TECs. The hermetic-sealed housing includes a first end with a feedthrough device that provides traces to electrically couple to the circuitry of the substrate. The hermetic-sealed housing further includes an optical coupling port, e.g., a LC connector, for coupling to an external fiber, for example.

Abstract: Techniques for flexible coupling between an optical coupling receptacle/port of an optical transceiver housing and optical components within the same are disposed. In an embodiment, an optical transceiver housing includes an intermediate fiber with a first end optically coupled to an optical coupling port and a second end optically coupled to a multiplexer/de-multiplexer device, e.g., an arrayed waveguide grating (AWG) device, PLC splitter, and so on. The intermediate fiber may be routed in the transceiver housing in a manner that and the radius of the bends may be optimized to reduce fiber bending losses. The techniques herein are equally applicable to both ROSA and TOSA modules and may be utilized to achieve flexible coupling for multi-channel transceiver devices.

Abstract: A photodiode package is disclosed that includes a TO-Can style body with an exposed sensor cavity that eliminates the necessity of an encapsulant dispensing process. The TO-Can body of the photodiode package includes an integrated coupling member to allow for coupling to a ROSA housing without an intermediate member. The photodiode package includes a base portion with a cylindrical wall portion that extends therefrom to form an optical coupling cavity. A surface of the base portion provides at least one mounting surface within the optical coupling cavity for coupling to a photodiode chip. The cylindrical wall may function as an integrated coupling member and may be used to directly couple the photodiode package, e.g., without an intermediate cap/ring, into a socket of a ROSA housing. The base portion and cylindrical wall may be formed from a single piece of material, or from multiple pieces depending on a desired configuration.

Abstract: A transceiver module having a partitioned housing, e.g., a bifurcated or multi-segment housing, is disclosed that allows coupling and alignment of a TOSA arrangement and ROSA arrangement in separate respective portions in order to minimize or otherwise reduce component damage and rework iterations during manufacturing and repair. Technicians may thus perform at least partial assembly and testing of each optical subassembly arrangement in parallel and in relative isolation without necessarily interrupting and/or waiting on completion of the other. In a general sense, each separate portion of the partitioned housing provides a dedicated workspace of about equal dimension for coupling of subassembly components. Each separate portion may lie flat on a tabletop, for instance, which may further simplify manufacturing processes and provide a wide-range of acceptance angles for performing soldering, welding, insertion and coupling of components, visual inspection, fiber routing, and so on.

Abstract: In accordance with an embodiment, a multi-layered flexible printed circuit (FPC) is disclosed that includes two or more insulating layers to route conductive traces carrying radio frequency (RF) signals, e.g., data signals, and conductive traces carrying direct current (DC) signals, e.g., power signals and low-frequency control signals, while sufficiently isolating the RF signals from electrical interference by the DC transmission lines. This advantageously eliminates having two or more separate FPCs to electrically couple each optical subassembly, e.g., receiver optical subassemblies (ROSAs) and transmitter optical subassemblies (TOSAs), to associated circuitry in a transceiver housing, which saves space and reduces manufacturing complexity, for example.

Abstract: A coaxial transmitter optical subassembly (TOSA) including a cuboid type TO laser package may be used in an optical transceiver for transmitting an optical signal at a channel wavelength. The cuboid type TO laser package is made of a thermally conductive material and has substantially flat outer surfaces that may be thermally coupled to substantially flat outer surfaces on a transceiver housing and/or on other cuboid type TO laser packages. An optical transceiver may include multiple coaxial TOSAs with the cuboid type TO laser packages stacked in the transceiver housing. The cuboid type TO laser package may thus provide improved thermal characteristics and a reduced size within the optical transceiver.

Abstract: A coaxial transmitter optical subassembly (TOSA) including a ball lens may be used in an optical transceiver for transmitting an optical signal at a channel wavelength. The coaxial TOSA includes a laser package with a ball lens holder section defining a lens holder cavity that receives the ball lens. The lens holder cavity is dimensioned such that the ball lens is positioned in substantial alignment with the laser diode for optically coupling a laser output from the laser diode into an optical waveguide at an optical coupling end of the TOSA. The coaxial TOSA is thus configured to allow the less expensive ball lens to be used in a relatively small package when a lower coupling efficiency and power is desired and without substantial redesign of the TOSA.

Abstract: A mirror device for use in an optical subassembly is disclosed that includes at least one surface with a visible indicator to allow a technician to differentiate a highly-reflective surface from relatively less reflective (e.g., un-coated) surfaces. The mirror device may be formed using known approaches, such as through the deposition of a metallic material on to a surface of the mirror device followed by one or more optional coating layers. Before, or after, forming the highly-reflective surface, a visual indicator may be introduced on to a surface of the mirror device that is opposite the highly-reflective surface. The visual indicator may comprise, for example, random scratches/scoring etched from a wire brush or tool, paint, epoxy, ink, or any other indicator that allows a technician to visually differentiate the portion of the mirror device having the visual indicator from the highly-reflective portion.

Abstract: A light engine is disclosed that includes an optical bench with a mirror etched therefrom to form a single, unitary structure. The integrated mirror may therefore be pre-aligned with an associated light path to reduce light path alignment errors. In an embodiment, the optical bench includes a first end extending to a second end along a longitudinal axis, a laser diode disposed on a mounting surface adjacent the first end of the optical bench and configured to output laser light along a first light path that extends substantially along the longitudinal axis, and an integrated mirror device disposed along the light path to receive and direct the laser light along a second light path to optically couple the laser light to a photonically-enabled complementary metal-oxide semiconductor (CMOS) die, the second light path being substantially orthogonal relative to the first light path.

Abstract: A coaxial transmitter optical subassembly (TOSA) with optical isolator alignment correction may be used in an optical transceiver for transmitting an optical signal at a channel wavelength. The coaxial TOSA includes an optical fiber coupling receptacle extending from a laser package. The laser package may include a laser diode and a lens to focus laser light emitted from the laser diode onto an optical fiber. The laser diode and lens are aligned along a first longitudinal axis of the laser package parallel to a transmission path of the laser light. An optical isolator located in the transmission path is aligned along a second longitudinal axis of the laser package. The second longitudinal axis is coincident with a centerline of the laser package, and the first longitudinal axis is offset from the second longitudinal axis by a predetermined offset distance to compensate for light shifting characteristics of the isolator.

Abstract: Techniques for reducing optical fiber bending loss in an optical transceiver are disclosed. In an embodiment, a small form-factor (SFF) optical transceiver housing includes a demultiplexer device, such as an arrayed waveguide grating (AWG) device, having a longitudinal center line that is offset laterally by a distance Doffset from the longitudinal center line of the SFF optical transceiver housing. The lateral offset distance Doffset may advantageously enable an intermediate optical fiber coupling the demultiplexer with an optical coupling receptacle, such as an LC connector, to be routed within the SFF optical transceiver housing in a manner that avoids introducing bends that are less than a minimum bending radius associated with the intermediate optical fiber cable. Thus some embodiments of the present disclosure enable greater tolerance when routing an intermediate optical fiber within housings that would otherwise introduce bending loss by virtue of their constrained dimensions.

Abstract: A heat transfer assembly may be used to provide a thermal conduit from a module mounted on a circuit board through the circuit board, allowing a thermal path away from the module. The heat transfer assembly generally includes a thermally conductive base with at least one raised thermal pedestal accessible through at least one heat transfer aperture in the circuit board and in thermal contact with the module. In an embodiment, the heat transfer assembly is used in a remote PHY device (RPD) in an optical node, for example, in a CATV/HFC network. The RPD includes an enclosure having a base with at least one raised thermal pedestal in thermal contact with an optical module (e.g., an optical transmitter or transceiver) on a circuit board through at least one heat transfer aperture in the circuit board.

Abstract: In accordance with an embodiment, a transmitter optical subassembly (TOSA) module is disclosed with a base portion that provides one or more mounting surfaces to mount a laser diode and associated driver circuitry in close proximity to allow for direct coupling without the use of an intermediate interconnect device, such as a flexible printed circuit or other interconnect device. The TOSA module base further includes a cylindrical shaped portion with a passageway extending therethrough. The substantially cylindrical shaped portion allows the TOSA module base to mount to a multi-channel TOSA housing via a Z-ring or other suitable welding ring without the use of an intermediate device such as a welding cap.

Abstract: An optical component holder having a base portion with a chamfered (or step) portion is disclosed herein that allows a technician to position and partially insert the same within an associated opening using a relatively minor amount of force. The chamfered portion of the base portion operates, in a general sense, as a guide that ensures proper alignment of the optical component holder and allows the same to travel a predetermined distance within the opening before being blocked from further travel by “bottoming” out when the wider portion of the base is at the edge of the associated opening. Thus, the chamfered portion provides an alignment feature to provide tactile feedback that indicates to the technician that the optical component holder is aligned and evenly inserted into an associated opening prior to supplying additional force to press the optical component holder fully into a housing.

Abstract: An arrayed waveguide grating (AWG) device for use in an optical transceiver is disclosed, and can de-multiplex an optical signal into N number of channel wavelengths. The AWG device can include an AWG chip, with the AWG chip providing a planar lightwave (PLC) circuit configured to de-multiplex channel wavelengths and launch the same into output waveguides. A region of the AWG chip may be tapered such that light traveling via the output waveguides encounters an angled surface of the tapered region and reflects towards an output interface region of the AWG chip. Thus detector devices may optically couple to the output interface region of the AWG chip directly, and can avoid losses introduced by other approaches which couple an output of an AWG to detectors by way of a fiber array or other intermediate device.

Abstract: Techniques are disclosed for providing relatively short distances between multi-channel transmitter optical subassemblies (TOSAs) and associated transmit connecting circuit in order to reduce losses due to signal propagation delays, also sometimes referred to as signal flight time delays. In an embodiment, a TOSA includes a plurality of laser assemblies disposed along a same sidewall of the TOSA along a longitudinal axis. The TOSA may be disposed within an optical transceiver housing in a transverse orientation, whereby a longitudinal center line of the multi-channel TOSA is substantially perpendicular to the longitudinal axis of the optical transceiver housing. The TOSA may be positioned adjacent an end of the optical transceiver housing having a transmit connecting circuit. Thus each of the plurality of laser assemblies may be positioned at a relatively short distance, e.g., 120 microns or less, away from the transmit connecting circuit.

Abstract: Energy reduction in a CATV network device, such as an optical node, in a CATV network may be accomplished using a system and method for controlling an amplifier in response to channel loading. The system and method detects a channel loading condition for a CATV RF signal including a plurality of utilized channels across a channel spectrum defining a plurality of potential channels. The channel loading condition may be detected by scanning the CATV RF signal to measure the channel loading or by obtaining channel loading data from a remote PHY device (RPD) located in the optical node. The system and method then obtains an amplifier operating parameter associated with the channel loading condition and applies the amplifier operating parameter to control power consumption of an amplifier in the optical node (e.g., by changing bias current) in response to the channel loading condition.

Abstract: A tunable laser with multiple in-line sections including sampled gratings generally includes a semiconductor laser body with a plurality of in-line laser sections configured to be driven independently to generate laser light at a wavelength within a different respective wavelength range. Sampled gratings in the respective in-line sections have the same grating period and a different sampling period to produce the different wavelengths. The wavelength of the light generated in the respective laser sections may be tuned, in response to a temperature change, to a channel wavelength within the respective wavelength range. By selectively generating light in one or more of the laser sections, one or more channel wavelengths may be selected for lasing and transmission. By using sampled gratings with the same grating period in the multiple in-line sections, the multiple section tunable laser may be fabricated more easily.