A first optical node is configured for deployment in an optical network including second optical nodes having a ring topology. The first optical node includes an optical encoder and a decoder. The optical encoder is configured to form a third optical signal for transmission into the optical network by combining a first optical signal generated by the first optical node with a second optical signal received by the first optical node from the second optical nodes. The decoder is configured to extract information from fourth optical signals received from the second optical nodes. In some cases, the first optical node includes a receive buffer configured to store information representative of the fourth optical signals received from the second optical nodes and a transmit buffer configured to store information used to generate the first optical signal.

A system and method for a tunable optical delay line. The tunable optical delay line comprises a coarse delay portion that provides a coarse delay amount, the coarse delay portion including a coarse delay selection element in conjunction with a coarse delay element, the coarse delay selection element incorporated on-chip into a photonic integrated circuit (IC) component, the coarse delay element being disposed off-chip of the photonic IC component and interconnected with the coarse delay selection element; and a fine delay element that provides a fine delay amount, the fine delay element interconnected in series with the coarse delay selection element, the optical delay line being tunable to a target delay amount by agglomerating the coarse and fine delay amounts.

Consistent with some disclosed embodiments, an optical switch includes: a scheduler; and a buffer for buffering an optical packet including, arranged in a circuit, a clock generator for generating a clock signal, an optical unbalanced Mach Zehnder Interferometer (MZI) and a fiber delay line (FDL) having an FDL length, wherein the optical packet has an optical packet signal, wherein the scheduler is configured to insert the optical packet into the buffer and to determine a number of circulations of the optical packet through the circuit, wherein the MZI modulates the clock signal based on the optical packet signal to create a reshaped optical packet after each circulation of the optical packet through the circuit, and wherein the FDL introduces a delay in the optical packet proportional to the FDL length.

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

Aspects of the disclosure involve a source node, having some predetermined knowledge of the optical network generating a list of nodes and/or optical links between nodes that form a route in the optical network from the source node to the destination node. The nodes in the optical network do not necessarily need to know the entire route from source node to destination node. Each node simply decodes the control information identifying the next hop in the route towards the destination node. By utilizing the decoded control information identifying the next hop, a switch in the node can be controlled to route the optical signal including the payload and some or all of the control information onto the next optical link toward the destination node.

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

Consistent with some disclosed embodiments, an optical switch includes: a scheduler; and a buffer for buffering an optical packet including, arranged in a circuit, a clock generator for generating a clock signal, an optical unbalanced Mach Zehnder Interferometer (MZI) and a fiber delay line (FDL) having an FDL length, wherein the optical packet has an optical packet signal, wherein the scheduler is configured to insert the optical packet into the buffer and to determine a number of circulations of the optical packet through the circuit, wherein the MZI modulates the clock signal based on the optical packet signal to create a reshaped optical packet after each circulation of the optical packet through the circuit, and wherein the FDL introduces a delay in the optical packet proportional to the FDL length.

A communication device is configured to receive data at a first data rate and to transmit the data at a second data rate that is greater than the first data rate. The communication device includes a plurality of communication pipelines and a multiplexer. Each communication pipeline is configured to receive a respective input data stream including first data blocks having a first format compatible for transmission at the first data rate, convert the first data blocks into second data blocks having a second format compatible for transmission at the second data rate, and provide an indication when one of the input data streams that is expected to be received is not received. The multiplexer is configured to receive the second data blocks from the communication pipelines and to generate an output data stream for transmission at the second data rate when one of the input data streams is not received.

A communication device includes a plurality of communication pipelines configured to receive respective input data streams and a multiplexer coupled to the plurality of communication pipelines. The multiplexer is configured to generate an output data stream by combining the input data streams and to insert one or more special characters into the output data stream in response to a fault with one of the communication pipelines.