- Deutsch Leverages Dot Hill AssuredSAN Arrays (LATEST) 03-06-2014
Dot Hill AssuredSAN is Ideally Suited for High Performance Digital Asset Management With Disaster Recovery and Replication Dot Hill Systems has announced that leading advertising firm Deutsch Inc. is leveraging Dot Hill AssuredSAN storage arrays as part of a digital asset management system with coast-to-coast data replication, supporting disaster...
- CyrusOne Begins Construction on Third Data Center at Houston West Campus (LATEST) 03-06-2014
CyrusOne is hosting a groundbreaking ceremony today at 11 a.m. Central Time for a third data center at its 45-acre Houston West data center services campus along Beltway 8 in Houston’s energy corridor. Upon completion, the new facility will include 428,000 square feet of raised floor capacity, 86,000 square feet of class A office space, and up to 96...
- Detecting software errors via genetic algorithms (LATEST) 03-05-2014
According to a current study from the University of Cambridge, software developers are spending about the half of their time on detecting errors and resolving them. Projected onto the global software industry, according to the study, this would amount to a bill of about 312 billion US dollars every year. "Of course, automated testing is cheaper", explains...
- OU study suggests non-uniform climate warming global (LATEST) 03-05-2014
Affects terrestrial carbon cycle, ecosystems and future predictions A recent University of Oklahoma study of five decades of satellite data, model simulations and in situ observations suggests the impact of seasonal diurnal or daily warming varies between global regions affecting many ecosystem functions and services, such as food production,...
- MIle2 Names Merit Training Center of the Year (LATEST) 03-05-2014
Merit Network has been selected by Mile2 as the North American Authorized Training Center (ATC) of 2013. Merit was chosen from over 100 Mile2 Authorized Training Center locations around the world. One ATC from each of five global regions was chosen to receive this annual award. Mile2 selected Merit for demonstrating a proven dedication to the...
- CFD simulations benefit surgeons making decisions on how to help their patients breathe easier (LATEST) 03-04-2014
A more accurate and successful, yet complex approach used in designing an airplane is now taking off in the health care industry. The end result is helping patients with pulmonary disorders breathe easier, as well as their surgeons in considering novel treatment approaches. Goutham Mylavarapu, a senior research associate in the University of...
- Cybergenetics TrueAllele Validated in Open-Access Scientific Study (LATEST) 03-04-2014
SuperComputers Interpret Rape Kits that Human Experts CannotMixtures of two or more people are the bane of forensic DNA laboratories. Hundreds of thousands of evidence items go unused because human analysts cannot interpret them. Cybergenetics TrueAllele Casework computer system can reliably preserve identification information in these cases, as...
- Merit Network Completes Network Upgrades for 2014 (LATEST) 03-04-2014
Critical paths upgraded to 100G and 40G Merit Network has completed several upgrades to its statewide, fiber-optic backbone. The upgrades bolster critical paths on Merit's core network to better support bandwidth exchange between Members and improve the flow of traffic to key interconnection points with Internet2, the Tier 1 Internet and content...
- Virginia Tech's Barbara Ryder to receive achievement award (LATEST) 03-03-2014
Barbara Ryder, the J. Byron Maupin Professor of Engineering and head of the Department of Computer Science in the College of Engineering at Virginia Tech, will receive the biennial Woman of Achievement award from the American Association of University Women of Virginia at its state conference at the W.E. Skelton 4-H Educational Conference Center at...
- Twitter big data can be used to monitor HIV and drug-related behavior, UCLA study shows (LATEST) 02-28-2014
Studying link between HIV, drug use could help prevention, detection efforts Real-time social media like Twitter could be used to track HIV incidence and drug-related behaviors with the aim of detecting and potentially preventing outbreaks, a new UCLA-led study shows. The study, published in the peer-reviewed journal Preventive Medicine, suggests it...
- NASA Researchers Help Hunt Ice Crystals Down Under (LATEST) 02-27-2014
NASA researchers are part of an international team working to improve aviation safety by studying high altitude ice crystals during a flight campaign now under way in Darwin, Australia.NASA and its North American partners are supporting the European Airbus-led High Altitude Ice Crystals (HAIC)/High Ice Water Content (HIWC) field campaign in the...
- Google Glass could help stop emerging public health threats around the world (LATEST) 02-27-2014
The much-talked-about Google Glass — the eyewear with computer capabilities — could potentially save lives, especially in isolated or far-flung locations, say scientists. They are reporting development of a Google Glass app that takes a picture of a diagnostic test strip and sends the data to computers, which then rapidly beam back a diagnostic...
- OpenMP ARB Releases New Mission Statement (LATEST) 02-27-2014
In recent years, OpenMP has shifted from being solely focused on shared-memory systems to also include accelerators, embedded systems, multicore and real-time systems. Today the OpenMP Architecture Review Board (ARB) releases a new Mission Statement to formalize this change. A technical report on directives for attached accelerators was first...
- Mouse brain atlas maps neural networks to reveal how brain regions interact (LATEST) 02-27-2014
Different brain regions must communicate with each other to control complex thoughts and behaviors, but relatively little is known about how these areas organize into broad neuronal networks. In a study published by Cell Press February 27th in the journal Cell, researchers developed a mouse whole-brain atlas that reveals hundreds of neuronal...
- Bull's profit falls 62% on lower supercomputer sales (LATEST) 02-27-2014
Bull said 2013 income fell 62%, as its sales were hurt by reduced supercomputer orders. In fourth quarter of 2012, Bull won several major supercomputer orders. Similar orders did not recur in 2013. Therefore, order intake decreased to €432.0 million in the fourth quarter. As a result, net income was €10.9 million in 2013, as opposed to €28.6...
- Software maps ambiguous names in texts to the right person (LATEST) 02-27-2014
If a name is ambiguous and given without context, even humans struggle. When reading the last name "Merkel", people do not know if it refers to the Chancellor of Germany Angela Merkel or the famous soccer coach Max Merkel. It is a drawback for web search, too. Up to now, the programs can capture character strings like "Angela Merkel", but they do...
- DOD Awards $70 Million for Digital Manufacturing, Design Innovation Institute (LATEST) 02-27-2014
SCRA to Manage the Consortium for the UI LABS-led Multi-Partner Team SCRA Applied R&D will act as the consortia manager for the recently announced Digital Manufacturing and Design Innovation (DMDI) Institute. United States President Barack Obama announced the award at a press conference yesterday. The federal investment for the DMDI Institute will...
- Offshore wind farms could tame hurricanes before they reach land (LATEST) 02-26-2014
Supercomputer simulations by Professor Mark Z. Jacobson have shown that offshore wind farms with thousands of wind turbines could have sapped the power of three real-life hurricanes, significantly decreasing their winds and accompanying storm surge, and possibly preventing billions of dollars in damages. For the past 24 years, Mark Z. Jacobson,...
- Merit Network, Center for Internet Security Collaborate (LATEST) 02-26-2014
Partnership will help public sector entities improve their cybersecurity Merit Network and Center for Internet Security (CIS) have announced today a collaborative partnership to help entities across the nation improve their cyber defenses by offering Michigan Cyber Range cybersecurity training courses and Merit Secure Sandbox service to state,...
- President Obama Announces Two New Public-Private Manufacturing Innovation Institutes (LATEST) 02-25-2014
A Detroit-area based consortium of 60 companies, nonprofits, and universities and a Chicago based consortium of 73 companies, nonprofits, and universities are partnering with the federal government to launch two new manufacturing innovation hubs. The first new manufacturing innovation institute competition this year is launching today, one of...
- Published: 31 August 2012
Demonstrates high-speed operation by integrating light source and optical modulator on the same silicon chip using structure that obviates need for thermal control mechanism
Fujitsu Laboratories Limited has announced the development of an integrated silicon optical transmitter for use in an optical transceiver(1), which is essential for enabling large volumes of data to be transmitted between CPUs.
Thermal fluctuations from the heat emitted by CPUs have a large impact on both the light source built into optical transmitters located near CPUs and the optical modulators(2) that encode data into the light emitted from the light source. This means a thermal control mechanism has been required to ensure that the operating wavelengths of both the light source and optical modulator consistently match. Fujitsu Laboratories previously devised a structure incorporating both the light source and optical modulator that did not require thermal control and demonstrated identical thermal properties by using separate prototypes of the light source and the optical modulator. This time, using the same structure to make a prototype optical transmitter that integrates the light source and optical modulator on the same silicon chip, Fujitsu Laboratories demonstrated that it could achieve optical modulation signals at speeds of 10 Gbps at temperatures ranging from 25ºC to 60ºC without a thermal control mechanism. Moreover, the overall electricity consumed by the optical transmitter was reduced by roughly half compared to previous methods.
This technology enables compact, low-power optical transceivers to be mounted directly in CPU packaging. Through its application exaflops-class supercomputers(3) and high-end servers requiring high-speed transmission of large volumes of data, the technology paves the way for super-high-speed computers.
Details of this technology will be presented at the 9th Group IV Photonics international conference (GFP 2012), running August 29-31 in San Diego.
In recent years, supercomputer performance has been roughly doubling every 18 months. Right now, work is underway to produce exaflops-class supercomputers with a target date around 2020. The creation of these ultrafast computers will require high-volume data transmission technology that allows individual CPUs to transfer data to each other at tens of terabits per second. With existing electrical interconnects based on copper wire, however, the dramatic increases required in circuit space, number of transmission lines, and electricity consumption in accordance with the higher data volumes are thought to make it difficult to achieve the data transmission speeds needed for exaflops-class supercomputers. As a result, consideration is being given to the use of optical interconnect technology in which, as shown in figure 1, CPUs are connected using light. Recently, in particular, attention is being focused on the development of silicon photonics(4) technology enabling optical transceivers to be compact and densely integrated, and that enables integration of electrical and optical components.
The transmitter component of an optical transceiver comprises a light source and an optical modulator that encodes data into the light emitted by the light source. A good candidate for the optical modulator is a ring resonator(5), as it is compact and energy efficient. But because the optical transceiver is located near the CPU, the lasing wavelength and the operating wavelength of the ring-resonator-based optical modulator do not coincide with each other due to heat from the CPU, resulting in information not being encoded in the light. A thermal control mechanism is needed to ensure that they match exactly, which, however, is an obstacle to making the transceiver compact and energy efficient.
By using the same ring resonator for both the wavelength control unit of the light source and the optical modulator, Fujitsu Laboratories previously devised a structure that made the wavelengths of the light source and optical modulator identical without the need for a thermal control mechanism. It used this structure to build separate prototypes of the light source and optical modulator, and it previously demonstrated that their thermal properties were identical.
Newly Developed Technology
This time Fujitsu Laboratories made a prototype optical transmitter that integrates on the same silicon chip a light source and optical modulator employing the previously devised structure. Using this transmitter, it demonstrated that it could make the wavelengths of the light source and optical modulator identical without the need for a thermal control mechanism and could achieve optical modulation signals at speeds of 10 Gbps at temperatures ranging from 25ºC to 60ºC.
Figure 2 depicts the prototype silicon optical transmitter that integrates the light source and optical modulator. To enable shifts in the wavelengths caused by temperature changes to match, the same ring resonator is used for both the wavelength control unit of the light source and the optical modulator. Moreover, to safeguard operation even if there are slight differences in the wavelengths of the light source and optical modulator, the optical modulator is structured with an alignment of multiple ring resonators, increasing the operating wavelength range. Using this structure, there is no need for a thermal control mechanism, and the overall electricity consumed by the optical transmitter was reduced by roughly half compared to previous methods. It is compact, measuring roughly only 2 mm long without the semiconductor optical amplifier. Through optimization using the silicon wire optical waveguide structure(6), it is expected that in the future the size can be reduced to under 1 mm.
Figure 3 depicts the optical modulation signals measured at speeds of 10 Gbps at varying temperatures. When varying the temperature from 25ºC to 60ºC, the spectrum's peak wavelength moves to the long-wavelength side, but a stable modulation signal is derived without controlling the wavelengths.
By further increasing the speed of this optical transmitter and integrating multiple transmitters on one chip using wavelength multiplexing technology, it will be possible to create optical transmitters small enough to be embedded into CPU modules capable of transmitting large volumes of data at rates of several terabits per second.
The use of this technology enables the development of exaflops-class supercomputers and high-end servers requiring energy efficient transmission of large volumes of data between CPUs, thereby paving the way for super-high-speed computers.
Fujitsu Laboratories plans to continue development of the optical receiver using the same silicon photonics technology, and will integrate it and this new transmitter to create a compact optical transceiver. Moreover, by applying wavelength multiplexing technology and pursuing dense integration, it will work on developing large-capacity integrated optical interconnects capable of enabling data transmission speeds of tens of terabits per second.
Glossary and Notes
- 1 Optical transceiver:
- A module that converts an electrical signal to an optical signal, which it then transmits, and that also receives an optical signal and converts to an electrical signal.
- 2 Optical modulator:
- An optical component that converts electrical signals to optical signals. These include intensity modulators that convert to an optical-intensity signal and phase modulators that convert to light-phase signals.
- 3 Exaflops-class supercomputer:
- A supercomputer that can process 10 to the18th "FLoating-point number Operations Per Second."
- 4 Silicon photonics:
- Technology in which a photonic device is configured on a silicon substrate. By using silicon, the optical circuits can be made smaller, enabling dense integration. It also has other merits, such as the ability to configure optical circuits and electrical circuits in one unit, and lower manufacturing costs.
- 5 Ring resonator:
- A resonator made of a ring-type optical waveguide. When used in silicon photonics, this can be made extremely small, with a radius on the order of microns. The ring's resonance effect makes it possible to create a highly efficient optical modulator.
- 6 Silicon wire optical waveguide structure:
- An extremely small silicon optical waveguide, in which the height and width of the cross-sectional surface is less than 1µm.