Embodiments of this application disclose an optical switch. The optical switch includes at least one first port, at least one second port, a first wavelength division multiplexing WDM apparatus, an optical splitter, an optical monitoring apparatus, and an optical switching apparatus. The first port is configured to transmit an input first optical signal to the first WDM apparatus, where the first optical signal is a multi-wavelength signal. The first WDM apparatus is configured to demultiplex the first optical signal. The optical splitter is configured to split a demultiplexed first optical signal to obtain a first sub-signal and a second sub-signal. The optical switching apparatus is configured to perform optical switching on the first sub-signal. The second port is configured to output a first sub-signal obtained after optical switching. The optical monitoring apparatus is configured to perform optical performance monitoring on the second sub-signal.

A wavelength division multiplexer/demultiplexer, a photonic integrated chip, and an optical module are provided. The wavelength division multiplexer/demultiplexer includes a substrate, a bus waveguide provided on the substrate, and at least two wavelength division multiplexing/demultiplexing units provided on the bus waveguide. Each of the at least two wavelength division multiplexing/demultiplexing units includes a mode multiplexer and an asymmetric Bragg grating. The mode multiplexer includes a first port, a second port, and a third port. The third port is connected to the asymmetric Bragg grating, so as to input a light in a TE1 mode or a higher-order mode to the asymmetric Bragg grating. The asymmetric Bragg grating transmits light containing wavelengths other than a wavelength λi. A grating period of the asymmetric Bragg grating and the wavelength λi satisfy a resonance condition.

Disclosed herein are methods, devices, and systems for providing timing and bandwidth management of ultra-wideband, wireless data channels (including radio frequency and wireless optical data channels). According to one embodiment, a hub apparatus is disclosed for providing out-of-band bandwidth management for a free-space-optical (FSO) data channel associated with a first device. The hub apparatus includes a processor, a memory coupled with the processor, an FSO transmitter coupled with the processor, and an FSO receiver coupled with the processor. The FSO transmitter may be configured to transmit a control signal comprising timing information and bandwidth management information.

In part, the disclosure relates to system. The system includes a polarization diversified wavelength demultiplexer (WDM). The polarization diversified wavelength demultiplexer includes a polarization beam splitter configured to output a first polarized signal and a second polarized signal based on an input signal; and a wavelength demultiplexer (WDM) having two inputs that are connected to the two outputs of the polarization beam splitter, and configured to output signals with a single set of outputs that carry signals of both polarizations, based on the first polarized signal from the first input and the second polarized signal from the second input.

Methods and apparatus for a reconfigurable optical add-drop multiplexer (ROADM) cluster node are provided. In some embodiments, the ROADM cluster node includes a set of g line chassis for performing line functionality. In some embodiments, the ROADM cluster node further includes a set of h add-drop chassis for performing add-drop functionality. In some embodiments, each of the g line chassis includes a set of N line cards and a set of M interconnect cards. In some embodiments, the ROADM cluster node further includes a set of M interconnect chassis configured for interconnecting each line chassis to each other line chassis. In some embodiments, the set of M interconnect chassis is further configured for interconnecting each line chassis to each of the h add-drop chassis. In some embodiments, the ROADM cluster node separates the line functionality and add-drop functionality. In some embodiments, 1.15N≤M≤1.5N.

Disclosed herein are methods, devices, and systems for providing timing and bandwidth management of ultra-wideband, wireless data channels (including radio frequency and wireless optical data channels). According to one embodiment, a hub apparatus is disclosed for providing out-of-band bandwidth management for a free-space-optical (FSO) data channel associated with a first device. The hub apparatus includes a processor, a memory coupled with the processor, an FSO transmitter coupled with the processor, and an FSO receiver coupled with the processor. The FSO transmitter may be configured to transmit a control signal comprising timing information and bandwidth management information.

Wavelength division multiplexers for space division multiplexing can include wavelength division multiplexing fanout devices or pump-signal combiners for multicore fibers.

A satellite system may have a constellation of communications satellites that provides services to users with electronic devices such as portable electronic devices and home/office equipment. The satellites may support communications between the electronic devices of the users and gateways. Each gateway may have satellite transceiver circuitry that transmits and receives satellite signals. Each gateway may also have an optical add-drop multiplexer coupled to a fiber ring and radio-frequency-over-fiber circuitry coupled between the satellite transceiver circuitry and the optical add-drop multiplexer. A metropolitan point-of-presence may be in communication with the fiber ring and may have modems for centrally processing communications (received and transmitted in an intermediate frequency) in the satellite system.

An optical filter comprising a first distributed Bragg reflector (DBR) layer, a second DBR layer, and an intrinsic semiconductor layer positioned between the first DBR layer and the second DBR layer, with the intrinsic semiconductor layer providing a passband wavelength for the optical filter based on a carrier density of the intrinsic semiconductor layer.

Example embodiments of the present invention relate to optical wavelength directing devices used to construct compact optical nodes.