RTC REPORT:   Winter 1997-98

Other RTC Reports

A Humboldt for Mukamel

RTC Senior member Shaul Mukamel, a chemistry professor, has been awarded a 1997 Humboldt Research Award in recognition of his lifelong research contributions. A member of the University of Rochester faculty since 1982, Mukamel is one of 80 American scientists to win this year's award.

He was nominated for the honor by Professor Eward Schlag of the Technical University of Munich. The award will enable Mukamel to conduct a year of research in Munich with Schlag and other European colleagues.

Mukamel is the author of the widely used text "Principles of Nonlinear Optical Spectroscopy" and has developed several novel ways to observe and interpret molecular dynamics. His research has focused on how to use the very brief laser pulses to shed light on activities such as the making and breaking of chemical bonds.

Delving into the field of biochemistry, he has examined how biological systems harvest light during photosynthesis and then convert that light into the chemical energy that makes life possible.

Mukamel earned his Ph.D. from Tel Aviv University in 1976 and held positions at MIT, Berkeley, Rice and the Weizmann Institute of Science in Israel before joining the University of Rochester faculty. He currently serves on the editorial board of the journal Chemical Physics Letters.

The Humboldt Research Award is sponsored by the Alexander von Humboldt Foundation of Bonn, an organization which works to foster international cooperation with leading German scientists.



From NRL to RTC


Dr. Scott Walck comes to RTC by way of the Naval Research Lab where he spent two years as a National Research Council Research Associate. Since his July 1997 arrival, he has worked with Professor D.J. Hall in The Institute of Optics on issues related to the coupling of metal island resonances and waveguide modes.

Asked to describe his most recent project, he explained that a waveguide is a structure which confines an electromagnetic field in one or two dimensions. One such structure is a planar semiconductor waveguide, in which a layer of semiconductor material with a high index of refraction is sandwiched between materials (perhaps insulating oxides) with lower indexes of refraction. The confined material, exists as a combination of waveguide modes.

Just as light is confined to the waveguide, and cannot escape to the outside, external light incident on the waveguide structure may not couple to the waveguide modes. The deposition of a metal island film on top of this semiconductor waveguide structure allows light incident on the surface to be coupled into waveguide modes (and also to be coupled out again). This process has potential application in small, high efficiency detectors of light, such as nanoscale photodetectors.

Dr. Walck chose this area of study because it can be developed using relatively simple classical mechanical models, and because it could provide interesting and easily accessible research opportunities for undergraduate students.

Walck received his Ph.D. from Lehigh University in 1995 under the direction of Professor W. Beall Fowler. His thesis was entitled "Vibrations of Hydrogen-Related Defects in Nonmetals: Quantum Mechanical Models".

He has collaborated with members of an experimental group at the University of Wuerzburg in Germany, a leading center of nanostructure fabrication., in the study of the excitonic properties of semiconductor nanostructures.



Postdoc Hu Huang is Right Back Where He Started From


University of Rochester graduate Dr. Hu Huang took a leave of absence from Tsinghua University in Beijing to return to his alma mater as a Junior Visiting Fellow at RTC. Working in conjunction with RTC's Dr. C.K. Law and the U of R's Professor N. Bigelow, he studied trapped photons and their motion in photonic band crystals. This resulted in three papers: "Lamb shift of absorptive resonance in Bose-Einstein condensates" (Phys. Rev. Lett.); "Dressed localized photon and atom states in a photonic band-gap crystal" and "Trapped photon state along an atomic chain embedded in a photonic band-gap crystal" ,both submitted to Phys. Rev. A.

Dr. Huang is currently working on the theory of Bose Enistein Condensate (BEC) ground state and collective motions in a nonsymmetric trap. The second involves the quantum electrodynamics effects of a group of atoms in a photonic band-gap crystal. His collaborators include Professor Nicholas Bigelow and his group, and Huang's colleagues and students in Beijing.

Huang would like to turn the result of his research into an application device. He says "it would take many steps and technical ingenuity. In the cases I described above, we analyse systems under unusual experimental conditions to discover important new properties under more conventional conditions. Tiny new devices may be built based on such studies. One might think that such devices must be expensive and fragile, but in the reality the course of development may be more favorable."

"Since the first BEC experiment two years ago, a mature technique has been developed and BEC now can be produced in a reliable way. Similarly, for ten years optical-range photonic crystals have been considered almost impossible to obtain; but a report from MIT just announced their success. These developments are great encouragement to us working on theories."

When Huang realized that his research projects had great potential for expansion, he was reluctant to leave RTC when his appointment ended. He requested and was granted a six month extension. In his letter to Director Eberly, Huang expressed his appreciation to RTC for "offering me such opportunity to be in such a productive environment".



A Patent Holding Engineer is RTC's Newest Postdoc


An interest in ultrashort pulsed beam propagation brought an electrical engineering major to RTC to interview for a postdoc position. When he heard that the Laboratory for Laser Energetics wanted someone to do research on wide bandwidth beam propagation Dr. John Marozas was ready to sign on the bottom line.

Notes Marozas, "I was trained as an engineer and worked as one for eight years. As a theorist I missed the 'hands-on work of an engineer. I enjoy getting my hands dirty working on hardware. So the postdoc position at LLE seemed to me to be a meaningful blend of the two worlds."

Currently he and others at the LLE are pursuing ways to uniformly distribute the energy of the laser beam in space and in time. One of the newly proposed ways of solving this problem is the use of a Distributed Polarization Rotator (DPR), which is simply a wedge of KDP, to spatially offset two orthogonal polarizations using the birefringence of KDP. This effect results in a decrease of the smoothing time by a factor of 2. Another method is called Smoothing by Spectral Dispersion (SSD) which puts bandwidth (about 10 Angs. is proposed) on the laser beam results in an improvement of the smoothing time at the target.

With the extremely high intensities used at LLE (on the order of GW/cm^2), distructive nonlinear self-focusing of small-scale ripple is always a concern. The introduction of the DPR has raised a question of how much ripple growth occurs due to the DPR.

Marozas received his Ph. D. from the University of Vermont. The title of his thesis was "Angular Spectrum Representation of Electromagnetic Pulse Propagation in Dispersive Dielectric Waveguides".

As a student he was employed at IBM as a research assistant and associate engineer. His work with a microwave oscillator earned him his first patent , awarded in April 1991 : Real Time Linearization and Temperature Compensation of a Voltage Controlled Oscillator's Non-Linearities Using a Spline Fit.

His 1998 RTC projects will include the design of an EO modulator to produce the 10 angs. of bandwidth.



Texas Sabbatical for Eberly

RTC Director Joseph Eberly is spending a six-month sabbatical at the University of Texas in Austin. In his absence, Robert Knox will serve as Acting RTC Director. Govind Agrawal has agreed to schedule the bi-weekly RTC postdoc seminars. Production of the RTC newsletter will be overseen by Emil Wolf.

RTC Postdoc Dr. C.K. Law and RTC graduate student Han Pu will spend several weeks in Texas in order to work with members of the the University of Texas Atomic-Molecular-Optic Group.



ALUMNI UPDATE

Joanne Law, an RTC graduate student, completed her Ph.D. in September 1997, under the supervision of Professor G.S. Agrawal. Her thesis title was "Optical-feedback effects on static, dynamic, and noise characteristics of vertical-cavity surface-emitting lasers". She is currently working in Fremont California for Therma-Wave.

Jim West, a student of Professor Carlos Stroud, Jr. has received his Ph.D. The title of his thesis was "Angularly localized wave packets in one- and two-electron atoms". He has accepted a research position with Corning.



SENIOR ACTIVITIES

Emil Wolf's 75th birthday was celebrated in Long Beach California, where a special workshop on Coherence and Physical Optics was held in his honor. The proceedings of the meeting, which are dedicated to Wolf, will be published in a special issue of the European Journal Pure and Applied Optics. Professor Wolf will spend spring semester 1998 in Florida where he will be a Distinguished Visiting Professor at CREOL, Central University of Florida.

The American Physical Society has appointed Carlos Stroud to be a Distinguished Traveling Lecturer in Laser Science. In October 1997, Stroud gave the Plenary Lecture at the Joint Meeting of the Optical and Atomic Division and the Molecular Division of the Canadian Association of Physicists in Ottawa. His lecture was entitled "Controlling the Structure and Dynamics of Atomic Electrons.

Shaul Mukamel has been honored with the 1997 Humboldt Research Award in recognition of his lifelong research contributions.



RTC Publications


"Far-zone Spectral Isotropy in Weak Scattering on Spatially random Media," E. Wolf, Opt. Soc. Amer. A 14, 2820-2832 (1997).

"Fractional wavefunction revivals in the infinite square well," D. Aronstein and C.R. Stroud, Jr., Phys. Rev. A 55, 4626-4537 (1997).

"Scattering in the Presence of Field Discontinuities at Boundaries," T. Visser and E. Wolf, Phys. Lett. A 234, 1-4 (1997).

"Reply to Eisenstein and Bunn's Comment on the Appropriate Null Hypothesis for Cosmological Birefringence," B. Nodland and J.P. Ralston, Phys. Rev. Lett. 79, 1958 (1997).

"Sources of Arbitrary State of Coherence which Generate Completely Coherent Fields Outside the Source," G. Gbur and E. Wolf, Opt. Lett. 22, 943-945 (1997).

"Visualization of core-scattering dynamics of Rydberg wave packets," J. West and C.R. Stroud, Jr., Opt. Exp. 1, 31-38 (1997).

"Coherence Filters and their Uses Part I: Basic Theory and Examples" E. Wolf, T. Shirai, H. Chen and W. Wang, J. Mod. Opt. 44, 1345-1353 (1997).

"Does excited chlorophyll-a equilibrate in solution ?," R.S. Knox, P.D. Laible, D.A. Sawicki, M.F.J. Talbot, J. Lumin. 72-74, 580-581 (1997).

"Excitons and their Equilibration," R.S. Knox, Pure & Appl. Chem. 69, 1163-1170 (1997).

"Statistical Generalizations of the Optical Cross-section Theorem with Applications to Inverse Scattering," P.S. Carney, E. Wolf and G.S. Agrawal, J. Opt. Soc. Amer. A 14, 3366-3371 (1997).

"Nonlinear spatio-temporal dynamics due to transverse-mode competition in gain-switched microcavity lasers," J.Y. Law and G.P. Agrawal, Opt. Commun. 138, 95-98 (1997).

"Decrease in Spatial Coherence of Light Propagating in Free Space," A.J. Devaney, A.T. Friberg, A. Kumar and E. Wolf, Opt. Lett. 22, 1672-1673 (1997).

"Effect of optical feedback on static and dynamic characteristics of vertical-cavity surface-emitting lasers," J.Y. Law and G.P. Agrawal, IEEE J. Sel. Top. Quantum Electron. 3, 353-358 (1997).

"Optical mixing of Rydberg angular momenta," J. Corless and C.R. Stroud, Jr. Phys. Rev. Lett. 79, 637-640 (1997).

"Determination of the Degree of Coherence of Light from Spectroscopic Measurements," D.F.V. James and E. Wolf, Opt. Lett. 145, 1-4 (1998).

"Shaping an Atomic Electron Wave Packet," M. Noel and C.R. Stroud, Jr., Opt. Exp. 1, 176-185 (1997).

"Propagation of a short laser pulse in a plasma," B. Nodland and C.J. McKinstrie, Phys. Rev. E. 56, 7174 (1997).



RTC Seminars


SEPTEMBER 1997

"Cavity QED 101: Single Photon Generator," Dr. C.K.Law, RTC Postdoc.

"Frequency and duration of the propagation of a laser pulse in a plasma," Dr. Borge Nodland, RTC Postdoc.

OCTOBER 1997

"Asymptotic Estimates of Wave Fields and Gaussian Packets," Miguel Alonso, Macquarie University, Australia. "Non-stationary theory of potential scattering of wave packets," Prof. Mikhail Fedorov, General Physics Institute, Russian Academy of Sciences, Moscow.

"Pondermotive Forces and Stimulated Compton Scattering," Prof. Mikhail Federov, General Physics Institute, Russian Academy of Sciences, Moscow.

"Consistent Histories, the End of the Line ?", Prof. Janos Bergou, Hunter College, CUNY, New York.

NOVEMBER 1997

"Nonlinear Spectroscopy of Single Molecules," Dr. Yang Zhao, RTC Postdoc.

"Four-Wave Mixing in Optical Fiber Links," Prof. Ildar Gabitov, Institute for Theoretical Physics, Dusseldorf, Germany.

JANUARY 1998

"Scars of Neutrally Stable Periodic Orbits," Dr. Paolo Bellomo, RTC Postdoc.



RTC Director:
J.H. Eberly

RTC Report:
Edited by C.S. Lavine
lavine@pas.rochester.edu

Mailing Address:
Rochester Theory Center for Optical Science and Engineering
University of Rochester, P.O. Box 270171
Rochester, NY 14627-0171, USA

Phone: (716) 275-3288



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