Embodiments of techniques for inverse design of physical devices are described herein, in the context of generating designs for photonic integrated circuits (including a multi-channel photonic demultiplexer). In some embodiments, an initial design of the physical device is received, and a plurality of sets of operating conditions for fabrication of the physical device are determined. In some embodiments, the performance of the physical device as fabricated under the sets of operating conditions is simulated, and a total performance loss value is backpropagated to determine a gradient to be used to update the initial design. In some embodiments, instead of simulating fabrication of the physical device under the sets of operating conditions, a robustness loss is determined and combined with the performance loss to determine the gradient.

Technologies for switching network traffic include a network switch. The network switch includes one or more processors and communication circuitry coupled to the one or more processors. The communication circuity is capable of switching network traffic of multiple link layer protocols. Additionally, the network switch includes one or more memory devices storing instructions that, when executed, cause the network switch to receive, with the communication circuitry through an optical connection, network traffic to be forwarded, and determine a link layer protocol of the received network traffic. The instructions additionally cause the network switch to forward the network traffic as a function of the determined link layer protocol. Other embodiments are also described and claimed.

An optical link for a communication network, the optical link having an optical fibre link, a downstream transmitter, a downstream receiver, an upstream transmitter and an upstream receiver. The upstream and downstream transmitters are configured to transmit a respective pilot tone on a respective optical carrier and are configured to tune a frequency of the pilot tone within a preselected frequency range. The upstream and downstream receivers are configured respectively to determine an upstream notch frequency, f.sub.notch-US, and a downstream notch frequency, f.sub.notch-DS, of respective detected photocurrents from at least one respective pilot tone frequency at which the respective detected photocurrent is equal to or lower than a photocurrent threshold. The optical link also includes processing circuitry configured to receive the upstream and downstream notch frequencies and configured to estimate a propagation delay difference of the optical link depending on the upstream and downstream notch frequencies.

A signal processing method and apparatus are provided. The method includes: receiving an optical signal in a target receive channel, and converting the optical signal into an electrical signal; determining, in the converted electrical signal, an electrical signal associated with a non-overlapping frequency band between the target receive channel and another channel, where the another channel is a channel that overlaps the target receive channel; and determining, based on the electrical signal associated with the non-overlapping frequency band, an electrical signal corresponding to a valid received optical signal that does not include an interfering optical signal in the target receive channel. According to the application, the target transmit channel and the another channel are set to channels that overlap each other, thereby reducing bandwidths occupied by the channels. In the method provided in the embodiments of this disclosure, spectrum utilization can be improved, thereby improving a data transmission rate.

A communications system has a transmitter circuit for transmitting a communications signal. The transmitter receives a plurality of input data streams and applies an orthogonal function to each of the plurality of input data streams. The transmitter groups the input streams having the orthogonal function applied thereto into a plurality of groups. The orthogonal functions applied to the plurality of input data streams do not repeat within the plurality of groups to limit interference between the input data streams within the group. The transmitter applies a different wavelength to each of the plurality of groups input data streams. The different wavelengths limit interference between the plurality of groups of input data streams. The transmitter applies a positive polarization and a negative polarization to each of the plurality of groups of input data having a different wavelength applied thereto. The positive and the negative polarizations are applied to a pair of groups having a same wavelength applied thereto limit interference between the pair of groups. The transmitter transmits the plurality of input of data streams over a plurality of channels on a communications link as the communications signal. Each of the plurality of channels has a unique combination of orthogonal function, wavelength and polarization associated therewith.

A communications system has a transmitter circuit for transmitting a communications signal. The transmitter receives a plurality of input data streams and applies an orthogonal function to each of the plurality of input data streams. The transmitter groups the input streams having the orthogonal function applied thereto into a plurality of groups. The orthogonal functions applied to the plurality of input data streams do not repeat within the plurality of groups to limit interference between the input data streams within the group. The transmitter applies a different wavelength to each of the plurality of groups input data streams. The different wavelengths limit interference between the plurality of groups of input data streams. The transmitter applies a positive polarization and a negative polarization to each of the plurality of groups of input data having a different wavelength applied thereto. The positive and the negative polarizations are applied to a pair of groups having a same wavelength applied thereto limit interference between the pair of groups. The transmitter transmits the plurality of input of data streams over a plurality of channels on a communications link as the communications signal. Each of the plurality of channels has a unique combination of orthogonal function, wavelength and polarization associated therewith.

A system for providing a residential IP network includes a plurality of transceiver circuitries, each associated with a building, for transmitting signals to/from the associated building. An optical network unit transmits and receives signals at a first frequency with an optical network. A remote unit integrated with the optical network unit converts the received signals at the first frequency into a first format that overcome losses caused by penetrating into the interior of the building over a wireless communications link and transmits the signals in the first format using beam forming and beam steering to provide the wireless signals to at least one of the plurality of transceiver circuitries. Each of the plurality of transceiver circuitries further includes first circuitry, located on an exterior of the building, for transmitting and receiving the signals in the first format. A first antenna associated with the first circuitry for transmits the signals in the first format into the interior of the building via a wireless communications link and receives signals from the interior of the building in the first format via the wireless communications link. Second circuitry, located on the interior of the building and communicatively linked with the first circuitry via the wireless communications link, receives and transmits the converted received signals in the first format that counteracts the losses caused by penetrating into the interior of the building from/to the first circuitry. A second antenna associated with the second circuitry transmits the signals in the first format to the exterior of the building via the wireless communications link and receives signals from the exterior of the building in the first format via the wireless communications link.

A system for providing a residential IP network includes a plurality of transceiver circuitries, each associated with a building, for transmitting signals to/from the associated building. An optical network unit transmits and receives signals at a first frequency with an optical network. A remote unit integrated with the optical network unit converts the received signals at the first frequency into a first format that overcome losses caused by penetrating into the interior of the building over a wireless communications link and transmits the signals in the first format using beam forming and beam steering to provide the wireless signals to at least one of the plurality of transceiver circuitries. Each of the plurality of transceiver circuitries further includes first circuitry, located on an exterior of the building, for transmitting and receiving the signals in the first format. A first antenna associated with the first circuitry for transmits the signals in the first format into the interior of the building via a wireless communications link and receives signals from the interior of the building in the first format via the wireless communications link. Second circuitry, located on the interior of the building and communicatively linked with the first circuitry via the wireless communications link, receives and transmits the converted received signals in the first format that counteracts the losses caused by penetrating into the interior of the building from/to the first circuitry. A second antenna associated with the second circuitry transmits the signals in the first format to the exterior of the building via the wireless communications link and receives signals from the exterior of the building in the first format via the wireless communications link.

An optical node device includes one or more input-side wavelength selection switches, a plurality of output-side wavelength selection switches, and an amplification unit. The input-side wavelength selection switches include a plurality of output ports, separate input light in accordance with a wavelength, and output the separated light from the output port corresponding to an output destination of the separated light. The output-side wavelength selection switches include input ports each receiving the light output from each of the one or more input-side wavelength selection switches, multiplex the light received from the input ports, and output the light. The amplification unit amplifies the light output from each of the output ports of the input-side wavelength selection switches and outputs the amplified light to the output-side wavelength selection switch at the output destination corresponding to the output port.

Embodiments of the invention describe apparatuses, optical systems, and methods for utilizing a dynamically reconfigurable optical transmitter. A laser array outputs a plurality of laser signals (which may further be modulated based on electrical signals), each of the plurality of laser signals having a wavelength, wherein the wavelength of each of the plurality of laser signals is tunable based on other electrical signals. An optical router receives the plurality of (modulated) laser signals at input ports and outputs the plurality of received (modulated) laser signals to one or more output ports based on the tuned wavelength of each of the plurality of received laser signals. This reconfigurable transmitter enables dynamic bandwidth allocation for multiple destinations via the tuning of the laser wavelengths.