Telefonaktiebolaget Lm Ericsson (publ)

The Royal Institution for the Advancement of Learning/mcgill University

Scuola Superiore Santanna

Ericsson Ab

Nicola Andriolli

Piero Castoldi

Antonella Bogoni

Luca Poti

Pier Giorgio Raponi

Mirco Scaffardi

Isabella Cerutti

Alberto Bianchi

Odile Liboiron-Ladouceur

Francesco Testa

Marzio Puleri

Marco Romagnoli

Gianluca Berrettini

Antonio Malacarne

Luigi Tallone

Md Shafiqul Hai

Philippe Velha

Gianluca Berettini

An integrated circuit optical interconnect for connecting a first circuit part arranged to output an optical signal and a second circuit part arranged to receive an optical signal. The integrated circuit optical interconnect comprises a body comprising a glass material. The glass material has embedded therein an optical waveguide arrangement having an input, located at a surface of the body, for coupling to the first circuit part, and an output, located at a surface of the body, for coupling to the second circuit part. The optical waveguide arrangement comprises at least two optical waveguide segments extending in different directions through the glass material and at least one reflecting part arranged between the two optical waveguide segments, for directing an optical signal from one of the optical waveguide segments to the other of the optical waveguide segments. The optical waveguide arrangement is arranged to optically couple the input and the output, whereby an optical signal can pass from the input to the output through the optical waveguide arrangement. There is also provided an integrated circuit module comprising the integrated circuit optical interconnect, and a telecommunications switch comprising the integrated circuit module. There is further provided a method for manufacturing an integrated circuit optical interconnect.

Integrated circuit optical interconnect

An optical switch () comprising: inputs () to receive input optical signals at respective wavelengths and having planar wavefronts; conversion apparatus () to convert each input optical signal into a respective optical signal having a respective helical wavefront, each helical wavefront having a different orbital angular momentum, OAM; optical multiplexing apparatus () to receive each helical wavefront optical signal from the conversion apparatus and to multiplex the helical wavefront optical signals into an OAM multiplexed optical signal; and optical demultiplexing apparatus () comprising a plurality of outputs (), the optical demultiplexing apparatus arranged to: receive the OAM multiplexed optical signal; demultiplex the OAM multiplexed optical signal into a plurality of wavelength multiplexed optical signals each having a different OAM; reconvert each wavelength multiplexed optical signal from its helical wavefront into a respective planar wavefront; and deliver each planar wavefront wavelength multiplexed optical signal to a respective one of the outputs according to the respective OAM it had before reconversion.

Optical switching

Optical solutions to address and overcome the issues of superseding/replacing electrical interconnection networks have generally exploited some form of optical space switching. Such optical space switching architectures required multiple switching elements, leading to increased power consumption and footprint issues. Accordingly, it would be beneficial for new optical, e.g. fiber optic or integrated optical, interconnection architectures to address the traditional hierarchal time-division multiplexed (TDM) space based routing and interconnection to provide reduced latency, increased flexibility, lower cost, and lower power consumption. Accordingly, it would be beneficial to exploit networks operating in multiple domains by overlaying mode division multiplexing to provide increased throughput in bus, point-to-point networks, and multi-cast networks, for example, discretely or in combination with wavelength division multiplexing.

Optical interconnection methods and systems exploiting mode multiplexing

Scalability and energy efficiency are key issues in data centers imposing tight constraints on the networking infrastructure connecting the servers. Optical interconnection mitigates electronic limitations but the additional flexibility offered by WDM and datarate across a data center interconnection network requires architectural design, photonic technologies, and operating strategies be selected and optimized to meet power consumption requirements. Multi-plane architectures based upon space-wavelength domain architectures have been proposed to overcome scalability limitations. It would be beneficial to extend space and time switching domains with the wavelength domain for additional capacity to increase throughput as well as providing same electro-optic interface. Accordingly, the inventors have established space-time domain interconnection network architectures with wavelength domain overlay overcoming power consumption issues, especially at low utilization, by exploiting all-optical implementations with active elements which act simultaneously as a switch and an amplifier, and the possibility to remain in an idle state when unused.

Methods and devices for space-time multi-plane optical networks

A method () of configuring a synchronous optical switch to route received data cells. The synchronous optical switch comprises optical switch transmitter modules, each comprising tunable optical transmitters, optical switch receiver modules, each comprising optical receivers, and optical connections between the transmitter modules and receiver modules. For each optical switch transmitter module, the method: assigns () wavelengths associated with the received data cells to the transmitters such that each wavelength is assigned to a different transmitter; and generates () a control signal for controlling the operating wavelength of each transmitter. For each wavelength, the method: allocates () to each transmitter an optical connection such that each optical switch transmitter module has no more than one connection exiting it at said wavelength and each optical receiver module has no more than one connection entering it at said wavelength; and generates () a control signal for connecting each transmitter to the respective optical connection.

Configuring synchronous optical switches

A node () for a multi-token optical communications network has optical channels between the node and other nodes, each channel having a token (T, T, T), passed between nodes, to indicate that a corresponding optical channel is available for transmission during a token holding time. The node has a transmitter () for transmitting packets over the optical channels, a buffer () for queuing packets before transmission, and a transmit controller () configured to control the buffer to forward an initial packet or packets from the buffer to the transmitter once a token has been received. The transmit controller determines how much of the token holding time remains after the transmission of the initial packet or packets, and then controls the buffer to forward a further packet according to the remaining token holding time. A maximum packet delay can be reduced where there is asymmetric traffic. A token holding time can be different for different nodes.

Control of token holding in multi-token optical network

An all-optical contention manager includes at least two inputs and at least two outputs. The outputs are configured to output signals to a Banyan switch. The contention manager detects and resolves routing contentions between incoming optical signals prior to outputting the signals to the Banyan switch. The signals have tags that include routing information. A photonic comparator in the contention manager compares the tags of incoming optical signals in order to detect contention.

All optical batcher banyan switch, batcher switch, banyan switch and contention manager

A synchronous packet switch comprises output modules, input modules, optical connections and a switch control unit. The output modules comprise optical receivers each configured to receive optical signals at a different wavelength. The input modules receive electric signals carrying data cells to be routed. Each input module comprises optical transmitters, each configurable to generate an optical signal at a different wavelength, and routing apparatus comprising output ports. Each output module has at least one output port allocated to it. The routing apparatus is configurable to route a received optical signal to a selected output port. The optical connections are arranged to couple output ports to respective output modules. The switch control unit controls routing of the optical signals from the transmitters to the output modules and generates a routing control signal for configuring the routing apparatus to route an optical signal from a transmitter to a selected output port.

Synchronous packet switches

An optical switch controller controls an optical interconnection network that variably connects at least one input data channel to a plurality of outputs channels via at least one switching element. An address reader module has at least one semiconductor optical amplifier optically processes an optical signal. The address reader module obtains information by reading a data tag from the input data channel, and outputs an address control signal based on the information. The address control signal can be used to control switching elements in the optical interconnection network.

Optical switch controller

An optical circuit comprises a bistable optical waveguide having first and second transmission states, and is more transmissive to light of a given wavelength in the second state than in the first state. First and second light sources emit light of first and second wavelengths, respectively, and are coupled to the waveguide at one end. Selectively transmitting a sufficient amount of light of the first wavelength through the waveguide switches the waveguide into the second state. Selectively transmitting a sufficient amount of light of the second wavelength through the waveguide switches it back to the first state. A sensing light source at the other end of the waveguide transmits a sensing light signal through the waveguide in the opposite propagation direction to that of light of the first and second wavelengths. A sensor detects the amount of the sensing light signal transmitted through the waveguide.

Growing community of inventors

Pisa, Italy

Nicola Andriolli