A technique related to a semiconductor chip is provided. An optical gain chip is attached to a semiconductor substrate. An integrated photonic circuit is on the semiconductor substrate, and the optical gain chip is optically coupled to the integrated photonic circuit thereby forming a laser cavity. The integrated photonic circuit includes an active intra-cavity thermo-optic optical phase tuner element, an intra-cavity optical band-pass filter, and an output coupler band-reflect optical grating filter with passive phase compensation. The active intra-cavity thermo-optic optical phase tuner element, the intra-cavity optical band-pass filter, and the output coupler band-reflect optical grating filter with passive phase compensation are optically coupled together.

The present disclosure relates to the field of communications technologies, and in particular, to an optical add/drop multiplexer, such that the optical add/drop multiplexer can ensure proper processing of light in two directions. The optical add/drop multiplexer can complete an extraction of a signal in one direction using one microring resonant cavity and two optical circulators, and if a wavelength of a signal in the other direction is the same as a resonant wavelength of the microring resonant cavity, the signal may reenter an optical network after passing through two microring resonant cavities and one optical circulator, and is not affected. Therefore, proper processing of optical signals in the two directions is ensured, and the optical signals in the two directions do not interfere with each other.

A method, computer-readable storage device and apparatus for routing traffic in a reconfigurable optical add-drop multiplexer layer of a dense wavelength division multiplexing network are disclosed. For example, the method determines the reconfigurable optical add-drop multiplexer layer has asymmetric traffic, and routes the asymmetric traffic in the reconfigurable optical add-drop multiplexer layer over a plurality of asymmetrical optical connections, wherein the plurality of asymmetrical optical connections is provided with only uni-directional equipment in the reconfigurable optical add-drop multiplexer layer.

Automatic optical link calibration systems and methods include an optical node with an Optical Add-Drop Multiplexer (OADM) multiplexer including a channel holder source; an optical amplifier connected to the OADM multiplexer and to a fiber span; an Optical Channel Monitor (OCM) configured to monitor optical spectrum before and after the optical amplifier; and a controller configured to obtain data associated with the fiber span including measurements from the OCM, determine settings of the channel holder source needed to meet a target launch power profile for the fiber span, and configure the channel holder source based on the determined settings.

We disclose an optical add-drop multiplexer that can apply different routing operations to different subcarriers of a data frame. In an example embodiment, the digital signal processor (DSP) of the optical add-drop multiplexer carries out subcarrier-specific add, drop, and pass-through operations in the electrical frequency domain, which enables the DSP to only partially unwrap the pass-through subcarriers, thereby at least partially avoiding some of the more processing-power-hungry DSP operations and reducing the sub-wavelength routing latency accordingly. Also disclosed is an example data-frame structure that can be used to provide subcarrier-specific routing instructions to the optical add-drop multiplexer.

Methods and systems for a bi-directional receiver for standard single-mode fiber based on grating couplers may include, in an integrated circuit, a multi-wavelength grating coupler, and first and second optical sources coupled to the integrated circuit: receiving first and second source optical signals at in the integrated circuit using the first and second optical sources, where the second wavelength is different from the first wavelength, receiving a first optical data signal at the first wavelength from an optical fiber coupled to the multi-wavelength grating coupler, and receiving a second optical data signal at the second wavelength from the optical fiber. Third and fourth optical data signals at the first and second wavelengths may be communicated out of the optoelectronic transceiver via the multi-wavelength grating coupler.

Coherent optical multiplexing 1+1 protection disclosed herein uses multiplexers, each having multiplexing and demultiplexing sub-units. Relay ports of a node are connected with the multiplexers, and each relay port is configured to input and output optical signals with the corresponding multiplexer. Two transmission ports of the node are connected with disjoint paths and are configured to input and output optical signals therewith. The node includes: a first optical splitter having input ports connected with the relay ports and two output ports connected with the two transmission ports; an optical switch connected with the transmission ports respectively via two input interfaces; a second optical splitter, which is a 1×N optical splitter, having one input port connected with an output interface of the optical switch and having output ports connected with the relay ports. The solution is reliable in implementation, has low insertion loss, and has good transmission performance.

Coherent optical multiplexing 1+1 protection disclosed herein uses multiplexers, each having multiplexing and demultiplexing sub-units. Relay ports of a node are connected with the multiplexers, and each relay port is configured to input and output optical signals with the corresponding multiplexer. Two transmission ports of the node are connected with disjoint paths and are configured to input and output optical signals therewith. The node includes: a first optical splitter having input ports connected with the relay ports and two output ports connected with the two transmission ports; an optical switch connected with the transmission ports respectively via two input interfaces; a second optical splitter, which is a 1×N optical splitter, having one input port connected with an output interface of the optical switch and having output ports connected with the relay ports. The solution is reliable in implementation, has low insertion loss, and has good transmission performance.

A device includes a module comprising an arrayed waveguide grating (AWG), and a filter having a filter input port, a filter output port, and a filter COMM output port. The filter is operable such that a first range of wavelengths entering the filter at the filter input port is directed to the filter output port and a second range of wavelengths entering the filter at the filter input port is directed to the COMM output port. The AWG includes an AWG input port optically coupled to the filter output port to receive the first range of wavelengths, and a plurality of AWG output ports.

A common component assembly is provided for a cable joint for joining a first submarine optical cable and a second submarine optical cable. The assembly includes a first end face including a first opening and a first flange for connection to a first cable termination unit of an undersea optical cable joint. The assembly also includes a second end face including a second opening and a second flange for connection to a second cable termination unit of an undersea optical cable joint. The assembly further includes a fiber tray connecting the first end face to the second end face. In addition, the assembly includes an optical assembly connected to a first side of the fiber tray. The optical assembly includes a free space optical add/drop multiplexer.