Abstract: A bidirectional optical subassembly (BOSA) optical networking unit (ONU) generally includes a BOSA housing. A tunable laser is located in the BOSA housing and is configured to generate a first optical signal for transmission at a first selected wavelength based on temperature control. The tunable laser is a distributed feedback (DFB) laser diode. A thermal management device is also located in the BOSA housing and is configured to provide the temperature control. A photo diode is further located in the BOSA housing and is configured to receive a second optical signal at a second selected wavelength. The BOSA housing comprises an alloy of stainless steel or an alloy of Kovar.

Abstract: A laser array optical coupling assembly may be used to couple a laser array to an arrayed waveguide grating (AWG), for example, in an optical transmitter in a wavelength division multiplexed (WDM) optical communication system. The laser array optical coupling assembly may include an optical fiber tip array with polished optical fiber tips providing a reduced mode field diameter to improve coupling efficiency with the laser array. The laser array optical coupling assembly may also include a direct coupling of the laser array to the AWG with modified AWG inputs reducing the mode field diameter to improve coupling efficiency with the laser array. The laser array optical coupling assembly may be used, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON) or in other transmitters or transceivers in a WDM system capable of transmitting and receiving optical signals on multiple channel wavelengths.

Abstract: A multi-channel optical transceiver includes a transmitter optical subassembly (TOSA) with a thermal arrayed waveguide grating (AWG) for multiplexing optical signals and a receiver optical subassembly (ROSA) with an athermal AWG for demultiplexing optical signals. The TOSA may also include a laser array optically coupled to the thermal AWG and a temperature control system thermally coupled to the laser array and the thermal AWG to control temperature for wavelength tuning. The temperature control system in the TOSA may include a thermoelectric cooler (TEC) that cools both the laser array and the thermal AWG. Because the athermal AWG in the ROSA is temperature independent, the ROSA does not include a TEC, thereby reducing power consumption and conserving space. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A thermally isolated multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The multi-channel TOSA generally includes an array of lasers optically coupled to an arrayed waveguide grating (AWG) to combine multiple optical signals at different channel wavelengths. The lasers, and possibly other components, are wire bonded to a thermal isolation bar. The thermal isolation bar provides an electrical connection to external circuitry and is thermally coupled to a temperature control device, such as a thermoelectric cooler (TEC). Thus, the thermal isolation bar electrically connects the lasers to the circuitry while preventing external heat from being conducted to the lasers from outside the TOSA. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: Individual channels of a multiplexed laser array in a multi-channel optical transmitter are monitored at an output of an optical multiplexer. The monitoring may be used to confirm proper operation of each of the channels in the multiplexed laser array and/or to perform wavelength locking on each of the channels. Monitoring at the output of the optical multiplexer avoids the use of multiple photodetectors coupled directly to multiple lasers in the multiplexed laser array. The multiplexed laser array generally includes a plurality of laser emitters optically coupled to an optical multiplexer such as an arrayed waveguide grating (AWG). An optical transmitter with a monitored multiplexed laser array may be used, for example, in an optical line terminal (OLT) in a wavelength division multiplexed (WDM) passive optical network (PON) or in any other type of WDM optical communication system capable of transmitting optical signals on multiple channel wavelengths.

Abstract: A multi-channel optical transceiver includes a multi-channel transmitter optical subassembly (TOSA), a multi-channel receiver optical subassembly (ROSA), and a dual fiber type direct link adapter directly linked to the multi-channel TOSA and the multi-channel ROSA with optical fibers. The dual fiber type direct link adapter is also configured to receive pluggable optical connectors, such as LC connectors, mounted at the end of fiber-optic cables including optical fibers for carrying optical signals to and from the transceiver. The dual fiber type direct link adapter thus provides the optical input and output to the transceiver for the optical signals received by the ROSA and transmitted by the TOSA. The multi-channel optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A thermally shielded multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The multi-channel TOSA generally includes an array of lasers optically coupled to an arrayed waveguide grating (AWG) to combine multiple optical signals at different channel wavelengths. A plurality of laser array thermal shields are thermally coupled to a temperature control device, such as a thermoelectric cooler (TEC), and thermally shield the respective lasers in the laser array in separate thermally shielded compartments. Each of the lasers may also be individually thermally controlled to provide a desired wavelength, for example, using a heater and/or cooler located in each thermally shielded compartment. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A tunable laser with multiple in-line sections generally includes a semiconductor laser body with a plurality of in-line laser sections each configured to be driven independently to generate laser light at a wavelength within a different respective wavelength range. The wavelength of the light generated in each of the laser sections may be tuned, in response to a temperature change, to a channel wavelength within the respective wavelength range. The laser light generated in each selected one of the laser sections is emitted from a front facet of the laser body. By selectively generating light in one or more of the laser sections, one or more channel wavelengths may be selected for lasing and transmission. The tunable laser with multiple in-line sections may be used, for example, in a tunable transmitter in an optical networking unit (ONU) in a WDM passive optical network (PON) to select a transmission channel wavelength.

Abstract: A multi-channel optical transceiver includes a multi-channel transmitter optical subassembly (TOSA), a multi-channel receiver optical subassembly (ROSA), and a dual fiber type direct link adapter directly linked to the multi-channel TOSA and the multi-channel ROSA with optical fibers. The dual fiber type direct link adapter is also configured to receive pluggable optical connectors, such as LC connectors, mounted at the end of fiber-optic cables including optical fibers for carrying optical signals to and from the transceiver. The dual fiber type direct link adapter thus provides the optical input and output to the transceiver for the optical signals received by the ROSA and transmitted by the TOSA. The multi-channel optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

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 bidirectional optical subassembly (BOSA) optical networking unit (ONU) generally includes a BOSA housing. A tunable laser is located in the BOSA housing and is configured to generate a first optical signal for transmission at a first selected wavelength based on temperature control. The tunable laser is a distributed feedback (DFB) laser diode. A thermal management device is also located in the BOSA housing and is configured to provide the temperature control. A photo diode is further located in the BOSA housing and is configured to receive a second optical signal at a second selected wavelength. The BOSA housing comprises an alloy of stainless steel or an alloy of Kovar.

Abstract: A heated laser package generally includes a laser diode, a heating resistor and a transistor in a single laser package. The heating resistor and transistor form a heating circuit and may be located on a submount adjacent to the laser diode. The transistor is configured to control the drive current to the heating resistor and any additional heat generated by the transistor may contribute to the heating of the laser diode and thus increase the thermal efficiency of the system. The heated laser package may be used in a temperature controlled multi-channel transmitter optical subassembly (TOSA), which may be used in a multi-channel optical transceiver. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A compact multi-channel optical may include a multi-channel transmitter optical subassembly (TOSA), a multi-channel receiver optical subassembly (ROSA) and a circuit board configured and arranged to fit within a relatively small space. The multi-channel ROSA is spaced from the circuit board to allow circuit components to be mounted between the circuit board and the ROSA. The multi-channel ROSA may also be inverted and mounted proximate a transceiver top housing portion, for example, using an L-shaped ROSA support, to transfer heat from the ROSA to the transceiver housing portion. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A temperature controlled multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The temperature controlled multi-channel TOSA generally includes an array of lasers optically coupled to an optical multiplexer, such as an arrayed waveguide grating (AWG), to combine multiple optical signals at different channel wavelengths. The lasers may be thermally tuned to the channel wavelengths by establishing a global temperature for the array of lasers and separately raising local temperatures of individual lasers in response to monitored wavelengths associated with the lasers. A temperature control device, such as a TEC cooler coupled to the laser array, may provide the global temperature and individual heaters, such as resistors adjacent respective lasers, may provide the local temperatures. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A heated laser package generally includes a laser diode, a heating resistor and a transistor in a single laser package. The heating resistor and transistor form a heating circuit and may be located on a submount adjacent to the laser diode. The transistor is configured to control the drive current to the heating resistor and any additional heat generated by the transistor may contribute to the heating of the laser diode and thus increase the thermal efficiency of the system. The heated laser package may be used in a temperature controlled multi-channel transmitter optical subassembly (TOSA), which may be used in a multi-channel optical transceiver. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A multi-channel receiver optical subassembly (ROSA) such as an arrayed waveguide grating (AWG), with outputs directly optically coupled to respective photodetectors such as photodiodes. In one embodiment, an AWG may be configured such that optical components of the AWG do not interfere with direct optical coupling, and the wire bonding points on the photodiodes may also be configured such that wire bonding does not interfere with direct optical coupling. The photodetectors may also be mounted on a photodetector mounting bar with a pitch sufficiently spaced to allow connection to floating grounds. A passive alignment technique may be used to determine the mounting locations on the photodetector mounting bar such that the photodetectors are aligned with the optical outputs.

Abstract: A compact multi-channel optical may include a multi-channel transmitter optical subassembly (TOSA), a multi-channel receiver optical subassembly (ROSA) and a circuit board configured and arranged to fit within a relatively small space. The multi-channel ROSA is spaced from the circuit board to allow circuit components to be mounted between the circuit board and the ROSA. The multi-channel ROSA may also be inverted and mounted proximate a transceiver top housing portion, for example, using an L-shaped ROSA support, to transfer heat from the ROSA to the transceiver housing portion. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A temperature controlled multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The multi-channel TOSA generally includes an array of lasers optically coupled to an arrayed waveguide grating (AWG) to combine multiple optical signals at different channel wavelengths. A temperature control system may be used to control the temperature of both the array of lasers and the AWG with the same temperature control device, e.g., a thermoelectric cooler (TEC). The multi-channel optical transceiver may also include a multi-channel receiver optical subassembly (ROSA). The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A temperature controlled multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The temperature controlled multi-channel TOSA generally includes an array of lasers optically coupled to an optical multiplexer, such as an arrayed waveguide grating (AWG), to combine multiple optical signals at different channel wavelengths. The lasers may be thermally tuned to the channel wavelengths by establishing a global temperature for the array of lasers and separately raising local temperatures of individual lasers in response to monitored wavelengths associated with the lasers. A temperature control device, such as a TEC cooler coupled to the laser array, may provide the global temperature and individual heaters, such as resistors adjacent respective lasers, may provide the local temperatures. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: An optical transceiver may include an optical fiber coupling assembly for coupling optical fibers to transmitter and receiver sub-assemblies to increase the number of usable channel wavelengths by reducing an incident angle on a WDM filter without causing unwanted back reflection to a laser. In one example, the optical fiber coupling assembly may be used to increase the number of usable channel wavelengths between the L-band and the C-band. The optical transceiver may be used, for example, in an optical line terminal (OLT) and/or optical networking unit (ONU) in a wavelength division multiplexed (WDM) passive optical network (PON) capable of transmitting and receiving optical signals on multiple channel wavelengths.