June 2015

In their Nature Photonics paper, Professor Shanhui Fan, graduate student Yu Shi, and alum Zongfu Yu show that, "when a signal is transmitting through, such isolators are constrained by a reciprocity relation for a class of small-amplitude additional waves and, as a result, cannot provide isolation for arbitrary backward-propagating noise. This result points to an important limitation on the use of nonlinear optical isolators for signal processing and for laser protection."

The Stanford News reports, "In previous works, researchers used a specific method to test whether nonlinear isolators on a chip could keep information flowing in the right direction. They would direct a beam of light in the "forward" direction and verify that the isolator would let the light through. Then they would direct a beam of light in the "backward" direction toward the isolator, and verify that the isolator would block that beam. It was not standard practice to test forward and backward beams at the same time."

This finding is important for designing isolators for optical chips. Engineers will need to look elsewhere for devices that can keep optical information flowing in one direction, but not the other.

Read full Stanford News article.

May 2015

"A new algorithm enables a moment-by-moment analysis of brain activity each time a laboratory monkey reaches this way or that during an experiment. It's like reading the monkey's mind," states the Stanford Report article.

Professor Shenoy and neuroscientist Matthew Kaufman, a previous student of Shenoy's, published the research findings in eLife.

Shenoy's lab focuses on movement control and neural prostheses — such as artificial arms — controlled by the user's brain.

"This basic neuroscience discovery will help create neural prostheses that can withhold moving a prosthetic arm until the user is certain of their decision, thereby averting premature or inopportune movements," Shenoy said.


Krishna Shenoy is Professor of Electrical Engineering and Courtesy Professor of Neurobiology.

March 2015

The university that pioneered research collaborations between academia and industry has expanded from a device-driven to a systems-level view of how to ignite innovation.

The shift involves a change in name and philosophy at what had been the Stanford Center for Integrated Systems (CIS).

Since the late 1970s, CIS had enabled Stanford researchers to work with industry counterparts to improve semiconductors, software, computers and other technologies. CIS helped create the global networks and mobile devices that put technology in our pockets.

Now, SystemX researchers are working on the next killer applications – the data center of tomorrow, the self-driving car, the smartphones with artificial intelligence built in and next-generation biomedical devices, among others.

Bringing these applications to fruition will require new materials and power sources, novel hardware and software, and coordination of these technologies through reliable control networks.

Stanford President John Hennessy, whose research helped revolutionize computing during the 1980s, describes this systems-level approach as the "technology stack."

"For 30 years, CIS was the model of industry-university partnership to support advanced research in microelectronics," Hennessy said. "SystemX is updating that model to spur innovation in what we call the technology stack and open up new possibilities for sensing, communication and computing technologies."

To highlight this change Stanford has rechristened CIS as the SystemX Alliance.


Read the full Stanford Report article

image of Assistant Professor Jonathan Fan
January 2015

The Air Force Office of Scientific Research (AFOSR) has announced the Young Investigator Research program (YIP) grant recipients. EE Assistant Professor Jonathan Fan's winning proposal will investigate Neuromorphic Infrared Nano-Optical Systems.

"The YIP is open to scientists and engineers at research institutions across the United States who received Ph.D. or equivalent degrees in the last five years and who show exceptional ability and promise for conducting basic research."

The AFOSR news article continues, "This year AFOSR received over 200 proposals in response to the AFOSR broad agency announcement solicitation in major areas of interest to the Air Force. These areas include: Dynamical Systems and Control, Quantum and Non-Equilibrium Processes, Information, Decision and Complex Networks, Complex Materials and Devices, and Energy, Power and Propulsion. AFOSR officials select proposals based on the evaluation criteria listed in the broad agency announcement. Those selected will receive the grants over a 3-year period."

Read the entire article

Wetzstein's research featuredScientific American’s features Assistant Professor Wetzstein’s Research as a World-Changing Idea as a world-changing idea
December 2014

In an article titled, "Smartphone Screens Correct for Your Vision Flaws," the December issue of Scientific American features Wetzstein's research with colleagues from MIT and University of California, Berkeley. The articles states, "Informal tests on a handful of users have shown that the technology works, Wetzstein says, but large-scale studies are needed to further refine it. In the process, the researchers also plan on developing a slider that can be used to manually adjust the focus of the screen. Wetzstein says that the technology could be a boon for people in developing countries who have easier access to mobile devices than prescription eyewear."

Gordon Wetzstein's research addresses challenges in computational imaging and display and in computational light transport. He received his PhD in computer science from the University of British Columbia in 2011, then worked at MIT's Media Lab as a research scientist and postdoctoral associate before joining the Stanford faculty.


Read the complete article from Scientific American.

Professors Wong and Mitra's CNT chips revealed at IEDM conference
December 2014

Professor H.-S. Philip Wong and Associate Professor Subhasish Mitra's research team has built a four-layer high-rise chip using carbon nanotubes (CNT) and resistive random access memory (RRAM). The new materials required a new method of connecting them, which were created by EE grad students, Max Shulaker and Tony Wu.

"This research is at an early stage, but our design and fabrication techniques are scalable," Mitra said. "With further development this architecture could lead to computing performance that is much, much greater than anything available today."

Wong said the prototype chip to be unveiled at IEDM shows how to put logic and memory together into three-dimensional structures that can be mass-produced.

"Paradigm shift is an overused concept, but here it is appropriate," Wong said. "With this new architecture, electronics manufacturers could put the power of a supercomputer in your hand."


Read the full article in the Stanford Report. 

Professors Hesselink and Rivas received Precourt Institute seed grants for their energy research
December 2014

Professor Lambertus Hesselink and Assistant Professor Juan Rivas-Davila are two of eight Stanford faculty seed grant recipients. The awards are to assist in new research that promises clean technology and energy efficiency.

Assistant Professor Juan Rivas' and his research team will continue exploration of more energy-efficient power supplies. An initial goal is to provide energy-efficient methods to pasteurize liquids like milk and fruit juice. The team's long-range goal is to revolutionize the design and manufacture of power electronics components. The Precourt Institute for Energy awarded Rivas-Davila's grant.

Professor Lambertus Hesselink's research will assess and design a method to capture heat waste from computers. His team projects that at least 20% of the waste could be recouped, saving $6 million in electricity per day in the U.S. alone. The Precourt Energy Efficiency Center (PEEC) provided this award.


Read the full Stanford report article.

Professor Jelena Vuckovic in her Nanoscale and Quantum Photonics Lab
December 2014

Published in a recent article in Scientific Reports, Professor Vuckovic and her team present the inverse design technique. As stated in the introduction, the "inverse design concept is simple and extendable to a broad class of highly compact devices including frequency filters, mode converters, and spatial mode multiplexers."

"Light can carry more data than a wire, and it takes less energy to transmit photons than electrons," said electrical engineering Professor Jelena Vuckovic, who led the research.

In previous work her team developed an algorithm that did two things: It automated the process of designing optical structures and it enabled them to create previously unimaginable, nanoscale structures to control light. Now, she and lead author Alexander Piggott, a doctoral candidate in electrical engineering, have employed that algorithm to design, build and test a link compatible with current fiber optic networks.


Read the article in Scientific Reports

Read the Stanford Report article 

Doctoral candidate Linxiao Zhu, Professor Shanhui Fan and research associate Aaswath Raman pictured with photonic radiative cooling material
December 2014

Professor Shanhui Fan and interdisciplinary team members from EE, ME, and Applied Physics, reported this energy-saving breakthrough in the journal Nature. Using a thermal photonic approach, the material reflects sunlight and emits heat, demonstrating new possibilities for energy efficiency. The photonic radiative cooler consists of seven alternating layers of hafnium dioxide (HfO2) and silicon dioxide (SiO2) of varying thicknesses, on top of 200 nm of silver (Ag), which are all deposited on top of a 200-mm silicon wafer.

The ultrathin, multilayered material can help cool buildings, reducing the need for air conditioning.


Image: Norbert von der Groebe

image of Professor Shan Wang, Joohong Choi and Adi Gani
November 2014

A team of Stanford University students and faculty has been selected as one of five Distinguished Award Prize winners in the Nokia Sensing XCHALLENGE, a global competition to catalyze breakthrough medical sensing technologies that will ultimately enable faster diagnoses and easier personal health monitoring.

The Stanford team was recognized for developing a hepatitis B blood test that can be analyzed in minutes using the microprocessor in a smart phone.

The current prize recognizes a 12-month effort by four PhD students – mechanical engineers Daniel Bechstein and Jung-Rok Lee, and electrical engineers Joohong Choi and Adi W. Gani – to create a mobile version of a technology that [EE Professor] Wang and other Stanford researchers have been developing for years.

In essence, the researchers graft magnetic nanoparticles onto biological markers. In this case they are interested in two biomarkers. One is the hepatitis B virus, called the antigen. The other is the antibody that fights hepatitis B. The magnetic particles are the homing beacons that allow instruments to track these biomarkers.


For the full story, visit

Image credit: Eigen Lifesciences


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