Research interests
My primary interests are in the field of nanoscale optical imaging
spectroscopy. The research objective of this lab is to develop
and apply new nanophotonic systems for the investigation of physical,
chemical and biological processes with nanometer-scale accuracy
and sub-picosecond time resolution. These new ultrasensitive spectroscopic
probing modalities will use linear and non-linear contrast mechanisms
as tools for better understanding condensed-phase and biological
structures in the quantum and single-molecule regimes.
Current projects
Plasmonic Devices: Optically Resonant Nanoantennas
Collaboration with Stefano Cabrini and the Nanofabrication of Nanostructures
Facility
The recent invention of single metallic optical nanoantennas has
greatly improved the mismatch between light and nanometer-scale
objects. Optical nanoantennas are specifically engineered to enhance
fields at visible and near-infrared (NIR) wavelengths and confine
them to regions ~ 10 nm in size, significantly defeating conventional
diffraction-limited resolution (~ 300 nm). Nanoantennas comprised
of plasmonically-coupled metallic nanoparticles offer appreciable
advantages over other near-field probes, most notably aperture-based
and apertureless near-field scanning optical microscopes (NSOM
and ANSOM, respectively). In particular, nanoantennas present much
greater near-field coupling efficiency than NSOM probes (efficiency
~ 30% for a bowtie versus ~10-5 for a typical metal-coated pulled
fiber probe) and significantly higher field enhancement than has
been measured for apertureless tips, creating an ultra-small, ultra-intense
light source. As nearly all scientific fields push toward a fundamental
understanding of processes on the molecular length scale, optical
nanoantennas offer an enticing method for enhancing the interactions
of light with nanoscale structures and for studying quantum systems.
An ultimate design goal is to place a nanoantenna on a scanning
probe, thus yielding an extremely intense near-field optical light
source with high local contrast that has applications as diverse
as ultrasensitive biological detection, nanolithography, high density
data storage and high resolution optical microscopy and spectroscopy.
Probing optical absorption and carrier dynamics in individual
carbon nanotubes
User project in collaboration with Dr. Feng Wang, David Cho, and
Prof. Y. R. Shen (U. C. Berkeley Department of Physics)
Carbon nanotubes are a family of nanostructures with unique mechanical,
electronic and optical properties. The basic understanding of these
properties, like for many other nanostructures, is frequently complicated
by inhomogeneous averaging in ensemble studies. Recent advances
in optical techniques capable of probing individual carbon nanotubes,
including fluorescence, Raman and Rayleigh scattering measurements,
have revealed much new information about carbon nanotubes and have
demonstrated the sensitive dependence of nanotube properties on
atomic structure, which we are investigating further through a
combination of high spatial, spectral and temporal resolution experiments.
Selected publications
- A. Sundaramurthy†, P. J. Schuck†, N. R. Conley,
D. P. Fromm, W. E. Moerner and G. S. Kino “Toward nanometer-scale
optical photolithography: Utilizing the near-field of bowtie optical
nanoantennas.” Nano Lett. 6, 355-360 (2006).
- D. P. Fromm,
A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino and
W. E. Moerner “Exploring the chemical enhancement
of surface-enhanced raman scattering with Au bowtie nanoantennas” J.
Chem. Phys rapid commun. 124, 061101 (2006).
- G. S. Kino, A. Sundaramurthy,
P. J. Schuck, D. P. Fromm, and W. E. Moerner, “Optical Field
Enhancement with Plasmon Resonant Bowtie Nanoantennas,” Chapter
9 of Surface Plasmon Nanophotonics, M. Brongersma and P. Kik, Editors
(Kluwer, Dordrecht, The Netherlands, appearing 2006).
- P. J. Schuck,
D. P. Fromm, A. Sundaramurthy, G. S. Kino and W. E. Moerner “Improving
the mismatch between light and nanoscale objects with gold bowtie
nanoantennas.” Phys. Rev. Lett.
94, 017402 (2005).
- P. J. Schuck, K. A. Willets, D. P. Fromm, R.
J. Twieg and W. E. Moerner “A novel fluorophore for two-photon-excited
single-molecule fluorescence.” Chem. Phys.- special issue
in honour of Daniel Chemla 318, 7 (2005).
- D. P. Fromm, A. Sundaramurthy,
P. J. Schuck, G. S. Kino and W. E. Moerner “Gap-dependent
optical coupling of single "bowtie" nanoantennas
resonant in the visible.” Nano Lett. 4, 957-961 (2004).
- J.
A. Matteo, D. P. Fromm, Y. Yuen, P. J. Schuck, W. E. Moerner and
L. Hesselink “Spectral analysis of strongly enhanced
visible light transmission through single C-shaped nanoapertures.” Appl.
Phys. Lett. 85, 648-650 (2004).
- P. J. Schuck, R.D. Grober, A.M.
Roskowski, S. Einfeldt, and R.F. Davis. “Cross-sectional
Imaging of Pendeo-epitaxial GaN Using Continuous Wave Two-photon
Micro-photoluminescence.” Appl.
Phys. Lett. 81, 1984 (2002).
- P. J. Schuck, M.D. Mason, R.D. Grober,
O. Ambacher, A.P. Lima, C. Miskys, R. Dimitrov, M. Stutzmann. “Spatially
Resolved Photoluminescence of Inversion Domain Boundaries in GaN
based Lateral Polarity Heterostructures.” Appl. Phys. Lett.
79, 952 (2001).
- R. D. Grober, J. Acimovic, J. Schuck, D.
Hessman, P.J. Kindlemann, J. Hespanha, A.S. Morse, K. Karrai,
I. Tiemann, S. Manus. “Fundamental
limits to force detection using quartz tuning forks.” Rev.
Sci. Instrum. 71, 2776 (2000).
Education
Stanford University, Postdoctoral Fellow, Department of Chemistry,
Advisor: W. E. Moerner, 2003-2006
Yale University, Ph.D., Department of Applied Physics, Advisor:
R. D. Grober, Dissertation titled “Three-Dimensional Imaging
Spectroscopy of the III-Nitride Material System, 2003
Yale University, M.S., Department of Applied Physics, Advisor:
R. D. Grober, 1998
U.C. Berkeley, B.A., Department of Physics, Research Advisor:
R. W. Falcone, 1997
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