Speaker:

Ming Wu

University of California at Berkeley

Title:

Optoelectronic Tweezers for Manipulating Cells and Nanowires

Host:

Stanley Pau

Abstract:

Optoelectronic tweezers (OET) is a new optical manipulation technique developed recently at UC Berkeley. Based on light-induced dielectrophoresis, OET can trap and sort colloidal particles and biological cells. It requires 100,000 times less optical power than conventional laser tweezers. As a result, we can use digital light projects to form massively parallel dynamic traps. As many as 31,000 individually addressable traps have been generated over an area of ~ 1 mm x 1 mm.  Recently, we have succeeded in trapping semiconductor and metallic nanowires (~ 100 nm diameter, a few micron in length). Once trapped, we can use the same optical beam to excite and measure the Raman spectra of the trapped single nanowire. Potentially, we can also use trapped nanowire as a SERS probe for in situ Raman characterization. Dynamic manipulation and sorting of biological cells using phototransistor-based OET will also be discussed.

Bio:

Ming Wu is Professor of Electrical Engineering and Computer Sciences at the University of California, Berkeley, and Co-Director of Berkeley Sensors and Actuators Center (BSAC). His research interests include MEMS, optoelectronics, and optofluidics. He received his M.S. and Ph.D. in Electrical Engineering from UC Berkeley in 1985 and 1988, respectively. Before joining the faculty of UC Berkeley, Dr. Wu was a Member of Technical Staff at AT&T Bell Laboratories, Murray Hill, from 1988 to 1992, and Professor of Electrical Engineering at UCLA from 1993 to 2004. In 1997, Dr. Wu co-founded OMM in San Diego, CA, to commercialize MEMS optical switches. He is an IEEE Fellow, a Packard Fellow (1992-7). He was recently awarded  the 2007 Engineering Excellence Award from the Optical Society of America. He has published over 440 technical papers, and holds 16 patents.

Speaker:

Syun-Ichi Akasofu

Title:

The Aurora

Host:

Stanley Pau

Abstract:

Aurora research has a long history of fascinating controversies.  However, my talk will focus on the progress of auroral science after the International Geophysical Year (IGY, 1957-58), in particular how it has led to the development of a new field, space physics, including interplanetary physics, magnetospheric physics, and physics of the heliosphere.  We are also working with solar physicists, because the sun is the ultimate energy source of the aurora.

 Taking this special opportunity, I would like to propose search for life on extra-solar system planets, using oxygen emissions, since free oxygen in their atmosphere is very likely to be released from plants.

 (I am greatly honored to be a co-author (with S. Chapman and A. B Meinel) of the article entitled, “The Aurora” in Handbuch der Physik (Vol. XLIX/1) published in 1966 (158 pp), although I have not had an opportunity to meet Dr. Meinel.)

Bio:

Dr. Syun-Ichi Akasofu is a professor of physics and director emeritus of the University of Alaska.  He was the director of the International Arctic Research Center at the University of Alaska Fairbanks since its establishment in 1999 until his retirement in 2007.  Prior to that, he was director of the UAF’s Geophysical Institute for 13 years from 1986 to 1999.  He helped establish the institute as a key research center in the Arctic, and played a critical role in the genesis of the Alaska Volcano Observatory and the modernization of the Poker Flat Research Range.

Akasofu came from Japan to the University of Alaska Fairbanks in 1958 as a graduate student to study the aurora under the guidance of Sydney Chapman, receiving his PhD in 1961.  He has been a professor of geophysics since 1964.  Akasofu has written more than 550 professional journal articles, and authored or co-authored 10 books.   Akasofu is an expert on the aurora borealis and the associated physics. His paper on the auroral substorm in 1964 is still cited often.  He initiated a study of space weather forecasting with K. Hakamada well before this issue became crucial.  The method they developed was refined by G. Fry and became the basis for the famous HAF model.

In 1976, the Royal Astronomy Society of London presented Akasofu with its Chapman Medal.  In 1980, UAF named Akasofu a Distinguished Alumnus.  In 1981 and again in 2002, he earned mention as one of the “1000 Most Cited Scientists.”  In 1985, Dr. Akasofu became the first recipient of the Chapman Chair Professorship at the University of Alaska Fairbanks; and in 1987, the National Association of State Universities and Land Grant Colleges named him as one of its  “Centennial Alumni.”  He has also been honored with the Japan Academy of Sciences Award, and the John Adams Fleming Award of the American Geophysical Union.

In addition, he has received awards of appreciation for his efforts in support of international science activities from the Ministry of Foreign Affairs of Japan in 1993 and from the Ministry of Posts and Telecommunications of Japan in 1996.  He was also the recipient of the University of Alaska Edith R. Bullock Prize for Excellence in 1997, and was named a Fellow of the American Geophysical Union in 1977, and of the American Association for the Advancement of Science in 2001.  He received the 1999 Alaskan of the Year Denali Award, and the 2003 Aurora Award from the Fairbanks Convention and Visitors’ Bureau. Also in 2003, the Emperor of Japan bestowed on him the Order of the Sacred Treasure, Gold and Silver Star.

Upon his retirement in 2007, the University of Alaska Board of Regents officially named the building that houses the International Arctic Research Center the “Syun-Ichi Akasofu Building” in recognition of “ his tireless vision and dedicated service to the university, the state, and country in advancing arctic science.”

Speaker:

Michael Cusanovich

Title:

PAS Domain Containing Light-Activated Switches

Host:

Stanley Pau

Abstract:

Photoactive yellow protein (PYP), a small (~15,000 mol. wt.) water soluble blue light sensor, is a member of a superfamily of PAS domain containing sensor proteins, and is the structural prototype for over 5,000 known PAS domain containing sensor proteins found throughout the evolutionary tree. PYP is a blue light sensor, however, the PAS superfamily is not restricted to light sensing, and depending on species functions can range from oxygen, electric field and redox sensing to small molecule sensing (for example, a wide range of small organic molecules and metabolites). The functional diversity of PAS domains is an outstanding example of the use of a common structural motif, which adapted through evolution to address the specific metabolic needs of a specific organism. PYP undergoes a photoisomerization (trans  p-hydroxy cinnamic acid to cis) in ~3 ps, that initiates a series of structural changes (photocycle) leading to the lit or signaling state, which then activates a response regulator leading to function. The lit state spontaneously reverts to the dark state to complete the photocyclye. The formation of the lit state is coupled with a major conformational change. Many of the PAS domain containing sensor proteins are complex consisting of two or more interacting domains.

A major focus of our work is on a blue-red light sensing protein, called Ppr, which contains PYP, bacteriophytochrome and histidine kinase domain, that phosphorylates a transcriptional regulator when activated, which turns on the expression of a polyketide synthase. Our goal is to characterize the transient structural changes leading to the lit state, and the mechanism by which the PYP, Bph and histidine kinase interact leading to the light activation of the kinase.

Photoactive Yellow Protein: A Prototypic PAS Domain Sensory Protein and Development of a Common Mechanism for the Two-Component Regulatory Family. M. A. Cusanovich and T. E. Meyer, Biochem. 42, 4759-70 (2003).

The Photoactivated PYP Domain of Rhodospirillum centenum  Ppr Accelerates Recovery of  the Bacteriophytochrome Domain After White Light Illumination.‘  John A. Kyndt, John C. Fitch, Terry E. Meyer, and Michael A. Cusanovich,  Biochem 46, 8256-62 (2007).

Speaker:

David Brady

Duke University

Title:

Snapshot Spectral Imaging, Focal Plane Interferometry and Compressive Imaging

Host:

Hong Hua

Abstract:

This talk describes coded aperture snapshot spectral imaging (CASSI) systems. CASSI systems rely on static aperture masks and decompressive data cube inference algorithms. We consider extensions of CASSI to alternative physical codes using interferometers or filters and we discuss application of snapshot spectral imaging to coherence imaging for 3D imaging and imaging through turbulence.

Bio:

David Brady is Professor of Electrical and Computer Engineering at Duke University, where he leads the Duke Imaging and Spectroscopy Program (www.disp.duke.edu). Professor Brady graduated from Caltech in 1990 and was on the faculty at the University of Illinois at Urbana-Champaign from 1990-2001, when he moved to Duke to become the founding director of the Fitzpatrick Institute for Photonics. He specializes in computational optical imaging and spectroscopy, with a recent focus on snapshot spectral imaging systems using compressive sampling and nonlinear signal inference, multiaperture imaging systems and on spatial coherence sensing.

Speaker:

Poul Jessen

University of Arizona College of Optical Sciences

Title:

Quantum Control of Atomic Spins

Host:

Stanley Pau

Abstract:

Laboratory techniques to manipulate and observe ultracold atoms make these a superb platform on which to develop and test new ideas in quantum control and measurement. I will discuss a series of recent experiments in which we use laser light and magnetic fields to drive non-trivial quantum dynamics of a large spin-angular momentum associated with an atomic hyperfine ground state. The resulting nonlinear spin Hamiltonian is sufficiently general to achieve universal quantum control over the 2F+1 dimensional state space, and allows us to generate arbitrary spin states and perform a full quantum state reconstruction of the result. We have implemented and verified time optimal controls to generate a broad variety of spin states, as well as an adiabatic scheme to generate spin-squeezed states for metrology. Most recently we have used our control and measurement tools to realize a popular paradigm for quantum chaos known as the kicked top. Direct observation of the phase space dynamics of this system has given us an unprecedented look at quantum/classical correspondence. In the future we hope to extend our toolbox for control and measurement of individual atoms and to apply it also to collective spins. Applications include quantum metrology, quantum information processing and simulations of quantum manybody physics.

Speaker:

Jun Ye

JILA, NIST, and University of Colorado

Title:

Quantum Metrology with Precision Light and Ultracold Atoms

Host:

Jason Jones

Abstract:

Improvements in spectroscopic resolution have been the driving force behind many scientific and technological breakthroughs over the past century, including the invention of the laser and the realization of ultracold atoms. State-of-the-art lasers can now maintain phase coherence over one second, that is, 10¹⁵ optical waves can pass by without losing track of a particular cycle. The recent development of optical frequency combs permits this unprecedented optical phase coherence to be established across the entire visible and infrared parts of the electromagnetic spectrum, leading to direct visualization and measurement of light ripples. A new generation of light-based atomic clocks has been developed, with ultracold Sr atoms confined in an optical lattice offering unprecedented coherence times for light-matter interactions. The uncertainty of this new clock has reached 1 x 10^-16, a factor of 3 below the current best Cs primary standard. These developments will have impact to a wide range of scientific problems such as the possible time-variation of fundamental constants and quantum simulations based on cold atoms, as well as to a variety of technological applications.  

Bio:

Jun Ye received his Ph.D. degree from the University of Colorado, Boulder, in 1997. He was a R.A. Millikan Postdoctoral Fellow at the California Institute of Technology from 1997-1999.  He has been a Fellow of JILA, the National Institute of Standards and Technology and the University of Colorado, since 2001.  He is a Fellow of NIST, a Fellow of the American Physical Society, and a Fellow of the Optical Society of America. His research interests include precision measurement, ultracold atoms and molecules, optical frequency metrology, and ultrafast science and quantum control. He has co-authored over 190 technical papers and has delivered over 200 invited talks. Awards and honors include I. I. Rabi Prize from the American Physical Society, Carl Zeiss Research Award, William F. Meggers Award and Adolph Lomb Medal from the Optical Society of America, Arthur S. Flemming Award, Presidential Early Career Award for Scientists and Engineers, U.S. Commerce Department group Gold Medal, Friedrich Wilhem Bessel Award from Alexander von Humboldt Foundation, and Samuel Wesley Stratton Award from NIST.  The research group web page is http://jilawww.colorado.edu/YeLabs/.

Speaker:

Dan Stancil

Carnegie Mellon University

Title:

Optical Nanocircuits Based on Microwave Analogies

Host:

Masud Mansuripur

Abstract:

There is now considerable interest in the fabrication of optical nanostructures for applications such as optical data storage, microscopy, and communications. In contrast with conventional integrated optics based on dielectric structures, metals are of particular interest owing to the potential for confining optical energy over regions as small as a few tens of nanometers. However, materials approximating “perfect conductors” do not exist at optical wave lengths, and surface Plasmon phenomena often lead to quite unexpected behavior.

In this talk we will examine the behavior of metallic two-conductor transmission lines, rectangular waveguides, and ridge waveguides at optical wavelengths. Procedures for applying Plasmon corrections to the classical microwave relations will be discussed, as a step toward the development of design procedures for optical analogues to microwave circuits. Applications will also be discussed, including the realization of sub-wavelength optical spots for optical data storage.

Bio:

Daniel D. Stancil is Professor of Electrical and Computer Engineering at Carnegie Mellon University. He received a B.S. in Electrical Engineering from Tennessee Technological University in 1976, and the S.M., E.E. and Ph.D. degrees from the Massachusetts Institute of Technology in 1978, 1979, and 1981, respectively. Prior to coming to CMU in 1986, he was an Assistant Professor of Electrical and Computer Engineering at North Carolina State University. At CMU he has served as Associate Department Head and as Associate Dean for Academic Affairs in the College of Engineering, as well as Thrust Leader for Optical Data Storage in the Data Storage Systems Center. He was a leader in the development of the CMU ECE department's Virtual Laboratory which was a finalist for a 1996 Smithsonian Computerworld Award. Electro-optics technology that he co-developed was recognized with an IR 100 Award and a Photonics Circle of Excellence Award in 1998. Dr. Stancil is a Fellow of the Institute of Electrical and Electronics Engineers, and a past-president of the IEEE Magnetics Society. His research interests include wireless communications, antennas, and applied optics.

Speaker:

Art Gmitro

Title:

A Tale of Two Projects

Host:

Stanley Pau

Abstract:

This talk will describe recent progress on two research projects in the Biomedical Imaging Laboratory. One project is aimed at the development, clinical demonstration, and validation of a confocal microendoscope for real-time in vivo optical biopsy. The other project involves development of multi-modality optical and magnetic resonance imaging of window chambers for studies of cancer and vascular biology.

Speaker:

Shibin Jiang

NP Photonics

Title:

Multi-Component Specialty Glass Fiber Lasers

Host:

Masud Mansuripur

Abstract:

Fiber lasers have attracted significant attention in last several years because of many technology breakthroughs and commercial business successes. Most fiber lasers use rare-earth ions doped silica fibers as the gain media.  However, in many cases silica fiber is not the ideal host. Multi-component specialty glass fibers are good alternatives because of their unique features such as low co-operative up-conversion coefficient, large mode field diameter, and short active fiber length. In this presentation, I will present highly erbium and ytterbium doped phosphate glass fibers for narrow linewidth single frequency fiber lasers near 1.5 and 1 microns, and thulium doped germanate glass fiber 2 micron fiber lasers with slope efficiency great than 70%. Brillouin fiber laser, Brillouin based fiber sensing, and potential application for wireless-over-fiber will be discussed. THz and GHz generation using Q-switched high power fiber lasers will also be described in this presentation.

Speaker:

James Harrington

Rutgers University

Title:

An Optical Fiber With a Big Hole or Infrared Hollow Waveguides: A Review

Host:

John Greivenkamp

Abstract:

Infrared-transmissive hollow waveguides (HWGs) are enjoying a resurgence resulting from emerging applications in a variety of sensor and power delivery systems. These HWGs consist of glass or polymer tubes with highly reflective metallic and dielectric coatings deposited on the inside surface. They are normally fabricated for transmission from transmit from 2 to 12 µm but they have also been made for the transmission of visible and THz radiation. Losses in the IR regime are less than 1 dB/m and lengths as long as 10 m have been made. The most successful structure has been the Ag/AgI coated hollow silica waveguides which are now being used to transmit broadband spectral information for thermal imaging and spectroscopy as well as for IR laser surgery. A brief history of the development of these unique structures will be given followed by a more detailed description of the optical properties of the HWGs. A variety of applications will be described including those involving laser power delivery in surgery, thermal imaging, and spectroscopy.

In addition to the technical presentation on hollow waveguides, I will also briefly describe my year working as a scientist at the Department of State. While there is generally a paucity of scientists at State, I found that scientists can play a key role assisting our foreign policy makers on science related issues. My year at State was spent as the science advisor for the control of dual-use, high technology items which the US controls either though the Department of Commerce or Defense (ITAR). I will review my year at State including examples of what types of technologies are controlled along with my work on visa related issues. During my year I have seen first hand the importance of science in the development of a sound foreign policy. Clearly there is an important role for a scientist at State yet I have learned that even though the science may be straightforward the path to achieving the final export controls is often filled with diplomatic potholes.

Bio:

Dr. Harrington has over thirty-five years of research experience in the area of optical properties of solids. Since 1977 he has worked on all aspects of infrared fibers including fabrication, characterization, and applications. He is generally recognized as one of the world's leading experts in this continually evolving field. His current research interests include the development of fiber optics for use in the delivery of laser power in surgical and industrial applications and for use as chemical and thermal fiber sensors. Specifically, these new fibers include hollow glass waveguides and solid core, single-crystal sapphire fibers for the delivery of CO₂, Er:YAG, and FEL laser radiation and for spectroscopic and thermometric applications aimed at the identification of chemical species and the measurement of low and high (>1500  C) temperature radiation. He is the inventor of hollow glass waveguides, which today are being used as CO₂ laser delivery systems in gynecology, arthroscopy, and dentistry. His book, Infrared Fibers and Their Applications, SPIE Press, January, 2004 provides a comprehensive overview of IR fiber optics and an entry point for those wishing to learn more about this growing field.

Dr. Harrington has spent many years in service to the optical community primarily through his professional association with SPIE, The International Society for Optical Engineering and through his work as a science advisor to the US Department of State. As member of SPIE’s leadership and in 2002 as President of SPIE he traveled extensively promoting optics research and education. He has met with many leaders in the US, Europe, and the far East to help arrange professional society meetings that promote not only many technical areas involving the broad field of optics but also to encourage many students to participate in professional conferences. Through his chairmanship of the US Advisory Committee of the International Commission on Optics (USAC/ICO), he has been very involved in working with a team of dedicated optics professionals to promote optics and photonics on a national level. During the 2005-2006, Dr. Harrington was a Jefferson Science Fellow at the US Department of State. He worked as a science advisor within the Bureau of International Security and Nonproliferation, Office of Conventional Arms and Threat Reduction (ISN/SATR) where he assisted in the establishment of controls for dual-use high technology goods. Specifically, his work with State, the Departments of Defense, Commerce, and the 40 nations making up the Wassenaar Arrangement helped establish controls for lasers and for low-light level sensors and cameras. His interests include control of dual-use technology, non-immigrant visas, and the application of non-life science and engineering solutions to improve the standard of living in less developed countries.

Speaker:

Bruce Tromberg

University of California, Irvine

Title:

Medical Imaging in Thick Tissues Using Diffuse Optics

Hosts:

Jennifer Barton and Arthur Gmitro

Abstract:

Medical diagnostic techniques based on near infrared (NIR) transillumination were first introduced more than 70 years ago to detect breast cancer.  Although NIR light penetrates tissue to depths of several centimeters, early methods were not successful due to the fact that these approaches were qualitative and did not account for distortions from multiple light scattering.

Recent advances in temporal- and spatial- frequency-domain “photon migration” now make it possible to separate light absorption from scattering in thick tissues. Temporal frequency-domain methods measure the phase shift and amplitude of MHz - GHz intensity-modulated waves, while spatial frequency-domain techniques utilize structured light patterns to form wide-field images of tissue optical properties.    Both approaches are based on comparing measured data with radiative transport models to acquire spectra and form images, i.e. diffuse optical spectroscopic imaging (DOSI).

This talk reviews principles of light propagation in tissue and describes the development of DOSI for non-invasively characterizing tissue structure and biochemical composition.  Particular emphasis is placed on broadband methods for quantitatively recovering NIR absorption and scattering spectra.  These data are used to determine the tissue concentration of deoxygenated hemoglobin, oxygenated hemoglobin, methemoglobin, lipid, and water, as well as the tissue “scatter power”. Clinical study results are shown highlighting the sensitivity of broadband DOSI to metabolic changes in breast cancer and in therapeutic drug monitoring.  Broadband spatial frequency-domain imaging is used in pre-clinical animal models to dynamically map intrinsic brain signals and monitor the efficacy of chemotherapeutic agents. These findings will be placed in the context of conventional imaging methods, such as MRI, in order to assess the current and future role of diffuse optics in medical imaging.