The Royal Institution for the Advancement of Learning/mcgill University

Scuola Superiore Santanna

Transfert Plus, Societe En Commandite

Valorbec L.p.

Odile Liboiron-Ladouceur

Md Shafiqul Hai

Nicola Andriolli

Isabella Cerutti

Meer Sakib

Monireh Moayedi Pour Fard

Piero Castoldi

Michael Menard

Christopher Williams

Pier Giorgio Raponi

Glenn Cowan

Philippe Velha

Mohammad Shafiqul Hai

Chunshu Zhang

There is described a photodetector for detecting incoming infrared light. The photodetector generally has a substrate; an i-type semiconductor region extending along the substrate, the i-type semiconductor region being sandwiched between a p-type semiconductor region and an n-type semiconductor region; a grating coupler being optically connected to one of two ends of the i-type semiconductor region, the grating coupler redirecting incoming infrared light into and along the i-type semiconductor region via the one of the two ends of the i-type semiconductor region for propagation of infrared light along the i-type semiconductor region; and a photocurrent detection circuit electrically connected to the p-type semiconductor region and to the n-type semiconductor region for detecting a photocurrent resulting from said propagation.

Photodetector for detecting incoming infrared light

As photonics evolves closer and closer to the electronic processing elements in order to meet the demands of speed, latency of evolving data communications networks and data centers the inventors, rather than seeking direct monolithically integrated CMOS based processing photonic and electronic elements, have established a different route. Namely replace the computer hubs/electrical bridges interconnecting the multiple core logic chipset elements with a photonic bridge. In this manner high risk chip-to-chip photonic point-to-point links are replaced with photonic SOCs that leverage photonics bandwidth density attribute rather than its bandwidth distance attributes. An SOI based Electronic Embedded Photonic Switching Fabric is presented supporting, for example, N&#xd7;MGb/s interconnections exploiting N channels of MGb/s wherein each channel of exploits S WDM channels of TGb/s. Embodiments of the invention also support high density optical interconnection via vertical grating couplers and multicore fibers.

Methods and systems for board level photonic bridges

Photonic integration has primarily sought to exploit optical parallelism through wavelength division multiplexing whilst in many instances 'brute-force' time division multiplexing offers benefits through reduced complexity and cost. However, photoreceivers are primarily the same now for operation at 10 Gb/s, 20 Gb/s, 40 Gb/s and above as 20 or 25 years ago and exploit the same optical detection&#x2014;amplification&#x2014;logic processing design. However, high speed low cost electronics ca be leveraged in conjunction with optical time sampling and logic to provide a new design paradigm. An incoming XGbsoptical data stream is sampled and processed by N photodetectors each operating at (X/N)Gbsrather than the current direct XGbsfront-end of the prior art. Flexibility for the designer in establishing N within optical layer constraints, electronics capabilities etc. allows for further cost&#x2014;power&#x2014;complexity&#x2014;performance tradeoffs to be established in different systems such that high capacity TDM links can exploit direct CMOS integrated optoelectronic front-ends.

Time sampled photodetector devices and methods

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

CMOS compatible SOI photonic integrated circuits (PICs) offer a low cost and promising solution to future short reach optical links operating beyond 100 Gb/s. A key building block in these optical links is the external optical modulator. Amongst, the PIC geometries for external modulators are those based upon ring resonators and Mach-Zehnder interferometers (MZI) where while the latter have been reported with increased thermal stability and fabrication tolerances, the former have demonstrated lower loss and lower driving voltages leading to a more energy efficient approach. Multi-segmented electrode structure based PAM optical modulator can potentially replace the analog digital-to-analog circuits (DACs) which are commonly used to achieve the multilevel electrical driving signal. Accordingly, it would be beneficial to combine the benefits of ring resonators to provide PAM-N modulators. It would be further beneficial for such PAM-N ring resonator modulators to exploit multi-segmented electrode structures to remove the requirements for high speed DACs.

Methods and devices for photonic M-ary pulse amplitude modulation

Broadband access networks are driving the upgrade of DWDM networks from 10 Gb/s per channel to more spectrally-efficient 40 Gb/s or 100 Gb/s. Signal quality degradation due to linear and non-linear impairments are significant and error control coding and signal processing solutions play increasingly key roles in meeting increasing demand, providing improved quality of service, and reduced cost. It would be beneficial to reduce the power consumption of optical receivers for optical links exploiting for example LPDC encoding. Accordingly, the inventors have established a low complexity soft-decision front-end compatible with deployable LDPC codes in next-generation optical transmission systems. Beneficially the optical receiver design can be retro-fitted into deployed hard-decision based optical systems and replaces the 3-to-2 encoder of the prior art in the electrical portion of the receiver with a single gate design. Further, the design may act as a 2-bit Flash ADC in multimode fiber based optical receivers.

Growing community of inventors

Montreal, Canada

Odile Liboiron-Ladouceur