Welcome! We are the research group of Jen Dionne, Assistant Professor of Materials Science and Engineering at Stanford University. We are a diverse team of materials scientists, electrical engineers, applied physicists, and chemists researching the design and development of new materials that allow light to be controlled in ways previously thought impossible. We then use these materials to directly visualize, probe, and control nanoscale systems and phenomena - particularly those relevant to energy and biology.
We aim to address questions such as: Can optical microscopy achieve a resolution comparable to electron microscopy, to study nanoscale systems in-situ and in real-time? Can sub-bandgap photons be efficiently harvested in solar cells, to improve solar energy conversion efficiencies? Can catalytic processes be probed on the single particle or molecule level, to understand and improve catalytic reactions? And, can proteins or small molecules be optically trapped and manipulated in-vivo, to directly probe molecular mechanics and interactions in cells? Though seemingly diverse, these questions all require precise control of light-matter interactions across wavelength and sub-wavelength scales, as enabled by new optical materials.
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When material dimensions approach the nanometer-scale, many unusual and exotic optical phenomena arise. In plasmonic and nanocrystalline metamaterials, these phenomena can include negative refraction, electromagnetic cloaking, and even quantum levitation. Research in our group is devoted to developing new solid-state and colloidal metamaterials and investigating their fundamental optical, electrical, and chemical properties. Ongoing projects include research into the electrodynamics of negative index materials, coupled plasmon-quantum dot systems, attractive and repulsive casimir forces, transformation optics, and single-nanoparticle nanophotonics.
Controlling light-matter interactions from classical down to quantum scales motivates applications ranging from solar energy conversion to sub-diffraction-limited microscopy. Currently, the Dionne group is focussed on three applications of plasmonic and nanocrystalline metamaterials: 1) developing efficient photovoltaic and photocatalytic systems for clean energy storage and environmental cleanup; 2) optically sensing and controlling neuronal transmission; and 3) exploring device applications of negative index materials, including sub-diffraction limited lenses and electromagnetic cloaks. All applications rely on the unique ability of plasmons and quantum dots to localize and enhance electromagnetic fields in unprecedented ways.
Latest News
June 7: Jen, Alice, Brian, and Guru shared the group's work at the first LAST (Life Art Science Technology) festival organized by Piero Scaruffi, alongside notable luminaries including Alvy Ray Smith, Co-founder of Pixar, Peter Norvig, Director of Research at Google, Daniel Kaufman, Director of the Information Innovation Office at DARPA, and Chris McKay, Chief Planetary Scientist at NASA Ames. Thank you, Piero, for organizing a stimulating festival!
June 4: Andrea delivered an invited talk on plasmon catalysis at the Canadian Chemistry Conference in Vancouver. Thank you, Ian Burgess, for organizing the symposium!
June 3: Ashwin delivered an invited talk on cathodoluminescence tomography at the first annual Electron Beam Spectroscopy workshop in Amsterdam. Thank you, Albert Polman and Javier Garcia Abajo for organizing this workshop!
May 27: Aitzol globe-trotted to Singapore and Australia, presenting two invited talks at Meta 2014 on non-Hermitian nano photonics and nanoantenna-enhanced CD spectroscopy, and another colloquium at Macquarie University on PT nanoantennas. His science has gone global!
May 21 : Jen presented the group's work at the SunShot summit in Anaheim, CA. Thank you, DOE for organizing an enriching workshop and review!
April 23 : Jon wins the MRS Gold Student award for his work on Quantum Plasmonic Materials and Metamaterials! Is that a smile we see during the ceremony? Congratulations Jon!! 
April 22 : MRS week is upon us! Jen delivered the opening invited talk in the 'Emerging Nanophotonic Materials and Devices' symposium, while Brian, Jon, Ashwin, Hadiseh, Tarun, Michael, and Diane shared the group's research on up conversion, non-Hermitian nanophotonics, quantum plasmonics, and nano-optical tomography in talks and posters throughout the week.
April 17 : Jen presented at the Berkeley Materials Science seminar. Thank you, Jie Yao and Mark Asta, for organizing my visit! Go bears!
April 14 : The D-Lab is awarded a PECASE! Jen got to tour the White House and meet President Obama! Thank you, DOD and NSF for the nomination!
April 4 : Jen presented at the Ohio University Physics colloquium. Thank you, Sasha Govorov and Ken Hicks for the invitation and great visit!
March 21 : The D-Lab is highlighted in GCEP's newsletter. Read the interview with Jen here.
March 17 : Hadiseh's paper is published in Physical Review A! Article: "Parity-time-symmetric plasmonic metamaterials"
March 10 : Jen presented at UIUC's Materials Science colloquium. Thank you, Prof. Cecilia Lea for hosting me and organizing a fun and stimulating visit!
March 8 : Jen, Diane, and Justin participated in the Physics of Sustainable Energy Conference at Berkeley - a lively discussion on next-generation renewable energy technologies. Thank you Barbara and Rob for the invitation to share our work on solar upconversion!
February 27 : Hadiseh's paper is published in Physical Review B! Article: "Non-Hermitian nanophotonic and plasmonic waveguides"
February 6-9:The D-Lab hits the slopes at our third annual Tahoe ski trip. Thanks to Andrea for organizing the trip!
February 5: Jen presented an invited talk at Photonics West on Broadband Metamaterials.
January 24: Jen presented an invited talk at the CIFAR-funded workshop on 'Energy, Biology, and Technology.' Thanks to Ted Sargent for hosting a very stimulating workshop!
January 22: Congratulations to Tarun for passing his qualifying exam! Not more than an hour later, he was back on the TEM!
January 8-10: The D-Lab completes another successful bootcamp!
January 6: The Dionne lab welcomes new members Alice Lay and Shing-Shing Ho!
Featured Research
I. Parity-time-symmetric metamaterials:
Inspired by insights from quantum mechanics, Hadiseh Alaeian has designed a new "parity-time-symmetric" plasmonic metamaterial that exhibits highly unusual unidirectional refraction, reflection and transmission coefficients that are both simultaneously greater than unity, and photonic Bloch power oscillations. This new metamaterial could be used to design lossless "perfect lenses" for optical imaging well below the diffraction limit of light, and well as unidirectional invisibility cloaks and new non-reciprocal nanophotonic devices. Her results are published in two articles, now available in Physical Review.
II. A Metafluid exhibiting strong optical magnetism:
In a recent Nano Letters, Sassan Sheikholeslami, Hadiseh Alaeian, and Ai Leen Koh describe protein-directed synthesis of a metamaterial fluid. The fluid exhibits an emergent magnetic response at visible frequencies, despite being composed of entirely non-magnetic building blocks. Their metafluid could enable new liquid-based tunable refractive index media with positive, negative, and near-zero refractive indices.
III. Surface enhanced circular dichroism spectroscopy:
Circular dichroism (CD) spectroscopy is a powerful technique in chemistry, molecular biology, and pharmacology, but it's sensitivity is limited. Chiral specimens exhibit a differential absorption of circularly polarized light that is orders of magnitude smaller than their absorption of unpolarized light. In a recent Physical Review B, Aitzol Garcia-Etxarri theoretically demonstrates how non-chiral nano-antennas can be used to enhance circular dichroism spectroscopy. The key is to use antennas that exhibit both electric and magnetic dipoles. This theory may form the basis for new solution or surface-enhanced CD spectroscopies with few-molecule sensitivity.
IV. A broadband negative index metamaterial at optical frequencies:
In the cover article of Advanced Optical Materials, Ashwin Atre, Aitzol Garcia-Etxarri, and Hadiseh Alaeian describe the mathematical design of the most broadband metamaterial to date, characterized by negative indices across hundreds of nanometers in the visible and near-infrared spectrum. Their results illustrate the power of transformation optics for designing new metamaterials and metasurfaces, and provide a foundation for future broadband superlenses, cloaks, or optical isolators.
