Boston University

Optical Characterization and Nanophotonics Laboratory








Selim Ünlü selected as a LEOS Distinguished speaker for 2005-2007

Prof. Ünlü was selected as a LEOS Distringuished speaker for 2005. His topic is "Nanoscale Imaging of Semiconductor and Biological Systems." The Distinguished Lecturer Awards program is designed to honor excellent speakers who have made technical, industrial or entrepreneurial contributions of high quality to the field of lasers and electro-optics, and to enhance the technical programs of LEOS chapters.

An abstract of his seminar is given below along with a schedule of confirmed and tentative talks.


M. Selim Ünlü is a Professor of Electrical and Computer Engineering, Biomedical Engineering, and Physics at Boston University. Prof. Ünlü received the B.S. degree in electrical engineering from Middle East Technical University, Ankara, Turkey, in 1986, and the M.S.E.E. and Ph.D. in electrical engineering from the University of Illinois, Urbana-Champaign, in 1988 and 1992, respectively. In 1992, he joined the Department of Electrical and Computer Engineering, Boston University.

Dr. Ünlü's career interest is in research and development of photonic materials, devices and systems focusing on the design, processing, characterization, and modeling of semiconductor optoelectronic devices, especially photodetectors, as well as high-resolution microscopy and spectroscopy of semiconductor and biological materials.

During 1994-1995, Dr. Ünlü served as the Chair of IEEE Laser and Electro-Optics Society, Boston Chapter, winning the LEOS Chapter-of-the-Year Award. He was awarded National Science Foundation Research Initiation Award in 1993, United Nations TOKTEN award in 1995 and 1996, and both the National Science Foundation CAREER and Office of Naval Research Young Investigator Awards in 1996. He has authored and co-authored over 250 technical articles and several book chapters and magazine articles; edited one book; and holds several patents. His professional service includes the former chair of the IEEE/LEOS technical committee on photodetectors and imaging and currently, the current chair of IEEE/LEOS Nanophotonics committee. He is also serving as an Associate Editor for IEEE Journal of Quantum Electronics and a VP of LEOS. Dr. Ünlü has been elevated to IEEE Fellow rank in 2007 for his contributions to optoelectronic devices.

"Nanoscale Imaging of Semiconductor and Biological Systems"

We present two innovative approaches to go beyond the capabilities of standard optical microscopy which is limited to a transverse resolution of approximately half a wavelength due to the diffraction, also termed the Rayleigh or Abbe limit. The resolution is inversely proportional to the Numerical Aperture (NA). One method to increase the NA is to increase n, the refractive index of the material in the object space. We recently developed a new technique involving a Numerical Aperture Increasing Lens (NAIL) for diffraction limited subsurface microscopy. The NAIL technique is demonstrated by near-IR inspection of Si integrated circuits yielding a 230 nm resolution at 1050 nm wavelength representing a factor of 4 improvement over the state-of-the-art. We have applied this technique to photoluminescence and PLE measurements of InAs/GaAs quantum dots and demonstrated high collection efficiency and spatial resolution better than 400 nm. We also used NAIL technique in subsurface thermal emission microscopy of Si integrated circuits and achieved improvements in the amount of light collected and the spatial resolution, well beyond the limits of conventional thermal emission microscopy. We experimentally demonstrate a lateral spatial resolution of 1.4 µm and a longitudinal spatial resolution of 7.4 µm, for thermal imaging at free space wavelengths up to 5 µm. We also examine in detail the ability of sharp metal tips to enhance local optical fields and describe a new approach to nano-optics, that of combining solid immersion microscopy with tip-enhanced focusing and show how such an approach may lead to 20 nm resolution with near-unity throughput.

Spatial resolution can also be improved beyond the diffraction limit by collecting spectral information. We have built on our experience on resonant optoelectronic devices and developed a novel application to fluorescence microscopy that promises nanometer resolution in biological imaging. Over the past 20 years fluorescence microscopy has developed into a standard tool in biological sciences. Today, confocal microscopy provides three-dimensional resolution on lateral length scales of 0.5 micron and axial length scales of 0.75 micron with good imaging speed for studies of biological systems. In the past few years, the increased resolution achieved through advanced fluorescent probes and two-photon sources has made possible the coarse examination of structures at the subcellular level, complementing decades of molecular biology with the nascent ability to localize subcellular processes. We have developed an alternative method, spectral self-interference fluorescent microscopy. The technique transforms the variation in emission intensity for different path lengths used in fluorescence interferometry to a variation in the intensity for different wavelengths in emission, encoding the high-resolution information in the emission spectrum. Using monolayers of streptavidin, we have demonstrated better than 5nm axial height determination for thin layers of fluorophores and built successful models that accurately fit the data. Initial experiments on fluorescently labeled lipid layers successfully determined the binding of fluorescent molecules in membranes with sub-nanometer precision. Recently, the orientation of ss and dsDNA monolayers on silicon oxide is studied by tracing the location of a fluorescent label attached to the DNA.

For sample slides for this talk (in pdf format) Special thanks to Dr. Stephen Ippolito for his invaluable contributions and pioneering efforts in the development of NAIL microscopy.

Schedule of Talks

confirmed - 2005

September 9, 2005
Friday (confirmed)
Lecture: 2:00pm

Hampton Roads LEOS Chapter
(Host: Prof. Amin Dharamsi, LEOS Chapter Chair)
Location: Old Dominion University, Webb Center, Chesapeake Room

October 11, 2005
Tueday (confirmed)
Lecture: 10:00am

Ottawa LEOS Chapter
(Host: Dr. John Bernard, LEOS Chapter Treasurer)
Location: NRC (Kelvin Room, M-36)

October 11, 2005
Tueday (confirmed)
Lecture: 6:30pm

Joint LEOS/MTTS/APS Montreal Chapter
(Host: Dr. Peter C. Noutsios, LEOS Chapter Chair)
Location: McGill University, Dept. of ECE, Rm. 603

October 13, 2005
Thursday (confirmed)
Dinner: 5:30pm
Lecture: 7:00pm

Central New England (Boston) LEOS Chapter
(Host: Dr. Matthew Emsley, LEOS Chapter Chair)
Location: Verizon Labs, 40 Sylvan Road, Waltham. Directions

December 14, 2005
Wednesday (confirmed)
Meeting social: 6:00pm
Lecture: 6:30pm

Washington-Northern Virginia LEOS Chapter
(Host: Dr. Lucy Zheng, LEOS Chapter Vice Chairman)
Location: A. V. Williams Building, Room 2460, University of Maryland
directions, map

confirmed - 2006

January 27, 2006
Friday (cancelled)

Los Angles LEOS Chapter
(Host: Prof. Changhuei Yang, LEOS Chapter Chair)

February 3, 2006
Friday (confirmed)
Lecture: 8:30am

Fort Worth LEOS Chapter
(Host: Prof. Weidong Zhou)
JSPS – UNT Joint Symposium on Nanoscale Materials for Optoelectronics and Biotechnology
Location: University of North Texas, Denton

February 21, 2006
Tuesday (confirmed)
Pizza: 4:45pm
Lecture: 5:00 pm

Northern NJ LEOS Chapter
(Host: Prof. Haim Grebel, Chapter Chair)
Location: Room ECE 202

May 9, 2006
Tuesday (confirmed)
Social/Pizza: 6:00pm
Lecture: 6:30pm

Santa Clara Valley LEOS Chapter - jointly with EDS Chapter
(Host: Dr. Brent Whitlock, LEOS Chapter Chair)
Location: National Semiconductor Credit Union Auditorium in Sunnyvale

May 15, 2006
Monday (confirmed)
Lecture: 8:30 am

Italian LEOS Chapter
(Host: Prof. Silvano Donati)
Location: Pavia

May 19, 2006
Friday (confirmed)
Refreshments: 7:00pm
Lecture: 7:30 pm

Denver LEOS Chapter - jointly with Rocky Mountain OSA (RMOSA)
(Host: Dr. Jeremy Haley Secretary/Treasurer Denver LEOS
Location: National Center for Atmospheric Research, Damon Room

June 1, 2006
Lecture: 11:00 am

Turkish LEOS Chapter
(Host: Prof. Volkan Demir, Vice Chair of the Turkish Chapter)
Location: Bilkent University, NANOTAM Conference Room

June 6, 2006

Scottish LEOS Chapter
(Host: Dr. Ajoy Kar, Chair of the Scottish Chapter)
Location: Strathclyde University

June 19, 2006
Monday (confirmed)
Lecture: 5:30 pm

Corning and Rochester LEOS Chapter
(Host: Dr. Sean Garner and Prof. Philippe Fauchet)
Location: Room 2101 at the Laboratory for Laser Energetics

September 8, 2006
Friday (confirmed)
Lecture: 1:30pm

LEOS Japan Chapter
A mini workshop with 2 other DLs: Prof. Baba and Dr. Notomi
(Host: Dr. Tetsuya Mizumoto, Secretary of Japan Chapter)
Location: Kousai Kaikan, Yotsuya, Tokyo

September 15, 2006
Friday (confirmed)
Lecture: 2:00 pm

Turkish LEOS Chapter
National Photonics Workshop (Ulusal Fotonik Calistayi)
(Host: Prof. Hakan Urey, Chair of the Turkish Chapter), Prof. Alper Kiraz, Workshop Chair
Location: Koc University

November 29, 2006
Wednesday (confirmed)
Lecture: 16:30 pm

University of Tübingen, Nano-Optics Department (also advertised to LEOS German Chapter)
(Host: Prof. Fredy Meixner)
Location: University of Tübingen, Germany

December 18, 2006
Monday (confirmed)
Lecture: 9:15 am

Max Planck Institute for Biophysical Chemistry (co-sponsored by LEOS German Chapter)
(Host: Prof. Stefan Hell)
Location: Department of NanoBiophotonics, Göttingen, Germany

confirmed - 2007

January 22, 2007
Monday (confirmed)
Lecture: 11:00 am

Singapore LEOS Chapter
(Host: Prof. Chin Mee Koy, Chair of the Singapore Chapter)
"Numerical Aperture Increasing Lens Microscopy for Quantum Dot and Integrated Circuit Imaging"
Location: NTU

January 23, 2007
Tuesday (confirmed)
Lecture: 10:00 am

Singapore LEOS Chapter
(Host: Dr. Teng Jinghua and Prof. Jacob Phang)
"Applications of Optical Resonance to Biological Sensing and Imaging"
Location: NUS / IMRE

September 15, 2007
Friday (confirmed)
Lecture: 1:30 pm

Anadolu University, Eskisehir
(Host: Prof. Servet Turan)
Location: Anadolu University, Material Science Conference Room

May 29, 2007
Tuesday (confirmed)
Lecture: 9:00 am

Benelux LEOS Chapter
(Host: Prof. Roel Baets)
"Applications of Optical Resonance to Biological Sensing and Imaging"
Location: University of Gent, Photonics Group Meeting Room directions

June 20, 2007
Wednesday (confirmed)
Lecture: 9:00 am

Lecture: 11:00 am

Canberra, LEOS Australia Chapter(Host: Prof. Chennupati Jagadish)
"Numerical Aperture Increasing Lens Microscopy for Quantum Dot and Integrated Circuit Imaging"
Location: Leonard Huxley Theatre
"Short Course on Photodetectors: Fundamentals, Bandwidth and Noise Considerations"
Location: School of Physical Sciences

June 21, 2007
Thursday (confirmed)
Lecture: TBD

"Short Course on High-resolution optical microscopy: Solid Immersion Lens and Subsurface Imaging using Numerical Aperture Increasing Lens"
Location: TBD

June 25, 2007
Monday (confirmed)
Lecture: TBD

University of Western Australia
(Host: Prof. Laurie Faraone and Prof. John Dell)
"Applications of Optical Resonance to Biological Sensing and Imaging"
Location: TBD

June 27, 2007
Wednesday (confirmed)
Lecture: TBD

Monash University or Melbourne University, LEOS Victoria Chapter
(Host: Prof. Premaratne, Monash U and Prof. Paul Mulvaney, Melbourne U)
"Applications of Optical Resonance to Biological Sensing and Imaging"
Location: TBD

June 28, 2007
Thursday (confirmed)
Lecture: pm TBD

Macquarie University, LEOS New South Wales Chapter
(Host: Prof. Deb Kane)
"Numerical Aperture Increasing Lens Microscopy for Quantum Dot and Integrated Circuit Imaging"
Location: TBD

June 29, 2007
Friday (confirmed)
Lecture: TBD

University of Technology, Sydney
(Host: )
Location: TBD



France LEOS Chapter
(Host: Philippe GALLION, Chair of the French Chapter)
Location: Paris


Poland LEOS Chapter
(Host: Wlodzimierz Nakwaski, Chair of the Poland Chapter)
Location: TBD


Toronto LEOS chapter
(Host: Dr. Fred Chang)


Houston LEOS Chapter
(Host: Prof. Dan Mittleman)


(Host: Sarper Ozharar, Vice Chair of LEOS CREOL Chapter)


Moscow LEOS Chapter
(Host: TBD)
Location: TBD

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