Abstract:
The present disclosure is generally directed to a stepped profile for substrates that support “on board” optical subassembly arrangements. The stepped profile enables mounting TOSA modules to the substrate in a recessed orientation to reduce the overall distance between terminals of the substrate and associated components of the TOSA, e.g., RF terminals of the substrate and an LDD of the TOSA. In an embodiment, the stepped profile further simplifies mounting and optical alignment of TOSA modules by providing at least one mechanical stop to engage surfaces of the TOSA modules and limit travel by the same along one or more axis.
Abstract:
The temperature at different locations along a multiplexed laser array may be monitored by sensing temperature at two locations within a transmitter optical subassembly (TOSA) package housing the laser array. The temperature at the two locations is used to determine a temperature tilt across the laser array. Estimated temperatures may then be determined at one or more other locations along the laser array from the temperature tilt. The estimated temperature(s) may then be used to adjust the temperature proximate the other locations, for example, for purposes of tuning lasers at those locations along the laser array to emit a desired channel wavelength. The TOSA package may be used in an optical transceiver 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. A switch module may be configured to couple a signal from a laser driver to a selected one of the plurality of in-line laser sections, wherein the signal modulates the laser light generated by the in-line laser section. The selected in-line section may be DC biased to a lasing state and the non-selected in-line sections may be DC biased to a non-lasing or transparent state.
Abstract:
A system is provided for improved coupling of photodetectors to optical demultiplexer outputs, for example an arrayed waveguide grating (AWG), using a refractive index matched material. In one embodiment, the system may include an optical demultiplexer including multiple optical outputs corresponding to multiple signal channels and a photodetector array including a plurality of photodiodes aligned with the multiple optical outputs. The system may also include an epoxy disposed within a gap between each of the photodiodes and each of the corresponding optical outputs of the optical demultiplexer. The epoxy may be configured to provide an index of refraction that is matched to the optical demultiplexer.
Abstract:
An optical transceiver generally includes an injection locked (IL) laser configured to generate a transmit (Tx) optical signal for transmission over an optical network and a laser driver circuit configured to modulate the IL laser based on a Tx data signal. The Tx data signal may be provided to the optical transceiver for transmission over the optical network. The Tx data signal may include a crossing point level associated with a transition between a first signal level and a second signal level. The optical transceiver may also include a crossing point control circuit configured to apply distortion to the Tx data signal, the distortion to increase the crossing point level.
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:
The present disclosure is generally directed to an optical transceiver module that includes a mounting section for aligning and coupling to associated TOSA modules. In particular, an embodiment of the present disclosure includes TOSA and ROSA components disposed on a printed circuit board assembly (PCBA). The PCBA includes a plurality of grooves at a optical coupling end to provide a TOSA mounting section. Each of the grooves provides at least one mating surface to receive and couple to an associated TOSA module. Opposite the optical coupling end, the PCBA includes an electric coupling section for coupling to, for example, a transmit (RX) circuit that provides one or more electrical signals to drive TOSA modules coupled to the TOSA mounting section.
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 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 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. A switch module may be configured to couple a signal from a laser driver to a selected one of the plurality of in-line laser sections, wherein the signal modulates the laser light generated by the in-line laser section. The selected in-line section may be DC biased to a lasing state and the non-selected in-line sections may be DC biased to a non-lasing or transparent state.