Disclosed herein is wavelength-division multiplexing (WDM) and demultiplexing with signal entry and exit in a common routing surface to increase channel density. In particular, disclosed is a WDM assembly including a plurality of common ports and a plurality of channel sets having one or more channel ports. The WDM assembly includes a first routing surface with a first WDM passband and a second routing surface offset from the first routing surface. The second routing surface is configured to reflect at least one signal passed through the first routing surface back through the first routing surface at a laterally different location. Optical signal paths of at least a portion of the common ports are parallel to and offset from one another. In certain embodiments, such a configuration may increase channel density and decrease a form factor (e.g., footprint).

A photonic interconnect apparatus includes tunable light devices, multiplexers to multiplex optical signals produced by the tunable light devices onto optical paths, and a cyclic arrayed waveguide grating (AWG) to receive the optical signals over the optical paths, and to direct a given optical signal of the received optical signals to a selected output of a plurality of outputs of the cyclic AWG based on a wavelength of the given optical signal. A respective demultiplexer directs the given optical signal to a selected output of a plurality of outputs of the respective demultiplexer according to which coarse wavelength band the wavelength of the given optical signal is part of.

Consistent with the present disclosure, an optical switch is provided that switches multiple wavelength division multiplexed (WDM) optical signals. Each of the WDM signals includes optical signals having the same wavelengths. The WDM signals are supplied to optical splitters, which supply power split portions of the WDM signals to corresponding optical gates. Groups of the optical gates are associated with a corresponding switching block, which may include a cyclical arrayed waveguide grating (AWG), and the optical gates within each group are controlled so that one gate passes a received WDM signal portion while the remaining optical gates in the group are in a blocking configuration. As a result, the WDM portion received by the non-blocking gate is demultiplexed in the switching block and each of the wavelength components that constitute the selected WDM portion are supplied to corresponding outputs within the switching block. In a later time interval, a different optical gate may be rendered non-blocking so that a different WDM signal portion, supplied from a different optical splitter and carrying different information over the same wavelengths, may be input to the switching block. Thus, by controlling the optical gates, different WDM signal portions may be switched to, and thus demultiplexed by, a particular switching block. In addition, portions of the same WDM signal may be selectively supplied to different AWGs by appropriately control of the optical gates.

An optoelectronic switch for transferring an optical signal from a source external client device to a destination external client device, includes a leaf rack unit having thereon a leaf switch assembly including: a leaf switch having a plurality of fabric ports including a first fabric port and a second fabric port; and a fabric port multiplexer associated with the leaf switch, arranged to combine a first signal from the first fabric port and a second signal from the second fabric port onto a first connection, in the form of an outgoing first multiplexed signal. The optoelectronic switch further includes a spine rack unit including: a plurality of spine switches including a first spine switch having a fabric port and a second spine switch having a fabric port; and a demultiplexer arranged to separate an incoming multiplexed signal received from a first connection into a first signal and a second signal, the first signal directed towards the fabric port of the first spine switch and the second signal directed towards the fabric port of the second spine switch.

A transmission device for which a work path is established in a first degree and a protection path is established in a second degree includes: a switch equipped with a plurality of optical ports; an optical signal generator, optically connected to a first optical port, and configured to generate an optical signal that is transmitted through the work path; and a monitor light generator, optically connected to a second optical port, and configured to generate monitor light by using a wavelength tunable light source. The monitor light generator controls a wavelength of the monitor light to be substantially the same as a wavelength of the optical signal. The switch guides the optical signal that arrives at the first optical port toward the first degree and guides the monitor light that arrives at the second optical port toward the second degree.

An optical receiver is described. Using silicon-photonic components that support a single polarization, the output of an optical receiver is independent of the polarization of an optical signal. In particular, using a polarization-diversity technique, the two orthogonal polarizations in a single-mode optical fiber are split in two and processed independently. For example, the two optical signals may be provided by a polarization-splitting grating coupler. Subsequently, a redistribution element provides mixtures of the two optical signals. Next, a wavelength channel in the two mixed optical signals is selected using a wavelength-selective filter (for example, using ring-resonator drop filters or an echelle grating) and converted into an electrical signal at an optical detector (such as a photodetector) to achieve polarization-independent operation.

An apparatus includes a first communication interface configured to be communicatively coupled, via an optical line, to a network device that is disposed in an optical network using wavelength division multiplexing (WDM). The apparatus also includes a second communication interface configured to be communicatively coupled to a router via an Ethernet connection. The apparatus also includes a signal generator operatively coupled to the first communication interface and the second communication interface. The signal generator is configured to generate an Ethernet signal representing at least one attribute of the optical line between the first communication interface and the network device. The second communication interface is configured to transmit the Ethernet signal to the router.

To provide an optical signal processing device that can collect light from an input waveguide to form a beam array having a small diameter. The optical signal processing device includes input waveguides 302a to 302c, an array waveguide 305 and a slab waveguide 304 that is connected to a first arc 304a having the single point C as a center and input waveguides 302a to 302c and that is connected to a second arc 404b having the single point C as a center and an array waveguide 305.

A processor of an optical transport apparatus is configured to transport an optical multiplexed signal between the optical transport apparatus and a counterpart apparatus by using a plurality of communication units; transmit an arbitrary optical wavelength from the optical multiplexed signal passing through ports by using a wavelength selective switch that has the ports respectively connected to the communication units; control a radio unit in the counterpart apparatus so as to change a frequency of the radio signal in the specified optical wavelength; and change a transmission band of the port through which the optical wavelength passes, according to a change of the frequency of the radio signal. The processor is configured to control an optical transmission unit of the counterpart apparatus so as to change a center wavelength of an optical wavelength passing through the port to a center wavelength of the changed transmission band of the port.

A data storage system is disclosed that includes a recirculating loop storing data in motion. The data may be carried by a signal via the loop including one or more satellites or other vessels that return, for example by reflection or regeneration, the signals through the loop. The loop may also include a waveguide, for example an optical fiber, or an optical cavity. Signal multiplexing may be used to increase the contained data. The signal may be amplified at each roundtrip and sometimes a portion of the signal may be regenerated.