The use of multimode optical fibers to boost the information capacity of the Internet is severely hampered by distortions that occur during the transmission of images because of a phenomenon called modal crosstalk.

However, University researchers at The Institute of Optics have devised a novel technique, described in a paper in Nature Communications, to “flip” the optical wavefront of an image for both polarizations simultaneously, so that it can be transmitted through a multimode fiber without distortion. The Rochester lab of Robert Boyd, professor of optics, collaborated with researchers at the University of South Florida and at the University of Southern California.

The solution the researchers devised involves digitally pre-shaping the wavefront and polarization of a forward-propagating signal beam to be the phase conjugate of an auxiliary, backward-propagating probe beam—in an experimental realization of vectorial time reversal.

“When an optical beam with perfect wavefronts passes through the multimode fiber, it comes out badly distorted,” explains Boyd, who is also the Canada Excellence Research Chair in Quantum Nonlinear Optics at the University of Ottawa.

“If we use a mirror to send the wavefront back, it will become even more distorted. But if we instead reflect it off a mirror, and also flip the wavefront from front to back, the distortion becomes undone as the waves go back through that distorting medium. In particular, we need to perform this procedure for both polarizations simultaneously when the distorting medium is a long multimode fiber.”

Lead author Yiyu Zhou, a PhD student in Boyd’s lab, says the technique could potentially be used to increase Internet speed by one or two orders of magnitude, and may have applications in improving endoscopy imaging of the brain and other biological tissues. Read more.

New findings from the Adolescent Brain Cognitive Development Study (ABCD) provide researchers with a roadmap of brain activity that could be used to identify cognitive processing problems that could ultimately contribute to mental and physical health problems later in life.

“This study pushes us closer to the point where we can identify and ultimately prevent mental health problems later in life by identifying risk early,” says John Foxe, director of the University’s Del Monte Institute for Neuroscience and co-author of the study, which appears in the journal Nature Neuroscience.   “If we can identify these risks with a simple brain scan at a young age, then that gives us a long runway to intervene and potentially change outcomes.”

The ABCD study, which was launched in 2016, is the largest brain development study ever undertaken by the National Institutes of Health.  The study has enrolled almost 12,000 youths aged 9 to 10 and will follow them for 10 years.  The study will seek to better understand how children’s experiences impact brain maturation and other aspects of their lives, including academic achievement, social development, behavior, and overall health. The University of Rochester Medical Center is one of 21 sites in the U.S. participating in the initiative and the local study is led by Foxe and Ed Freedman.

Using functional magnetic resonance imaging (fMRI) technology, the researchers observed brain activation during a battery of three different tasks and identified how differences in the patterns of activity related to individual differences in these processes.  The findings from the new study demonstrate which brain regions are involved in a range of important psychological processes, including cognitive control, reward processing, working memory, and social and emotional function. Read more.

• Thomas Brown ’87 (PhD), professor of optics, and Sina Ghaemmaghami, associate professor of biology and the director of the Office of Undergraduate Research. They are the latest recipients of the Mercer Brugler Distinguished Teaching Professorships at the University. Established in 1979, the professorships are announced every three years and are held by the recipients until the next round of awards. This is not the first time Brown and Ghaemmaghami have been recognized for exceptional contributions to undergraduate teaching. They both also received the University’s Goergen Award for Excellence in Undergraduate Teaching in 2017.
• Gretchen Roman, Population Health Research Postdoctoral Fellow at the University’s Clinical and Translational Science Institute (UR CTSI), for being awarded a mini-grant from the Center for Community Health and Prevention. For her fellowship, Roman is assessing the well-being and adaptability of sign language interpreters who have been working remotely during the COVID pandemic. With the new mini-grant, she will partner with the Greater Valley Region Registry of Interpreters for the Deaf to get member feedback and disseminate study findings. Learn more about the mini-grant awards and the process for submitting an application.
• Stephen Johnson, a PhD candidate in musicology, and Stephanie Venturino, a PhD candidate in music theory, who are the 2021-22 recipients of Ball Fellowships, which recognize outstanding potential as a scholar in the humanities, economics, or business administration. Johnson’s dissertation will cover North Korean revolutionary opera and the ways it both constructs and responds to juche ideology across the twentieth century. Venturino’s dissertation will focus on the concept of resonance in French music and music theory from 1900 to 1960. She will examine its wide-ranging influence on music-theoretical discussions of harmonic dualism, consonance and dissonance, and scale formation, as well as show dualist structures in contemporaneous compositional practice.
• Eight chemistry graduate students who have been selected to serve as the Graduate Student Symposium Planning Committee for the American Chemical Society’s 264th National Meeting in Chicago, IL, August 21-25, 2022. It is the first time that University of Rochester students have been chosen to serve as the GSSPC. Karla Rosalia Sanchez Lievanos, Maria Camila Aguilera, Geemi P. Wellawatte, Eric Schreiber, Shilpa Bhatia, Aleksa Milosavljevic, Dasha Rodina, and Anees Keedakkatt Puthenpeedikakkal will organize a full-day symposium, entitled “Achieving Scientific Excellence through Interdisciplinary and Collaborative Research.” Read more.

A new Rochester Early-Stage Investigator (RESIN) program will optimize and support training for early-stage researchers from across the translational spectrum.

The bimonthly series will kick off at noon July 14 with Conducting Clinical and Translational Research: How the UR CTSI Can Help, an hour-long overview of what the University’s Clinical and Translational Science Institute has to offer presented by Carrie Dykes, Jeanne Holden-Wiltse, and Edwin van Wijngaarden.

The series is being launched by the UR CTSI in collaboration with clinical and basic science departments and the Office for Faculty Development at URMC.

The UR CTSI’s Center for Leading Innovation and Collaboration now offers a Career Development Community, an interactive space where CTSA Program members and the greater translational science community can collaborate, network and share ideas with their peers from across the consortium.

The community has three focus areas: clinical research professionals, TL1 trainees and KL2 scholars. Each area includes a message board, highlighted content section, and searchable user list to foster communication, networking and collaboration.