Michael Downer
http://www.ph.utexas.edu/dept/research/downer/
updated 2-19-07
Personal
Born
Married
Citizenship
July 19, 1954, Rockville Centre, New York
Jane Castledine, August 22, 1993
U.S.A.
Education
Ph.D.
M.A.
B.A.
Harvard University
Oxford University, Brasenose College
University of Rochester
1983
1978
1976
Applied Physics N. Bloembergen, supervisor
Physics
Physics
Career Positions
Professor of Physics
Associate Professor of Physics
Assistant Professor of Physics
Postdoctoral Member Technical Staff
University of Texas at Austin
University of Texas at Austin
University of Texas at Austin
AT&T Bell Labs, Holmdel, NJ
1997 - present
1991 - 97
1985 - 91
1983 - 85 C. V. Shank, supervisor
Honors/Awards
College of Natural Sciences Distinguished Professor
1
Farrington Daniels Award (American Assoc. Physicists in Medicine)
2
Fellow, Optical Society of America
President’s Associates Teaching Excellence Award, UT-Austin
Teaching Excellence Award, College of Natural Sciences, UT-Austin
Outstanding Graduate Teaching Award, UT-Austin
3
Fellow, American Physical Society
Jack S. Josey Professorship, U T-Austin
Research Fellow, Center for Ultrafast Optical Science, U. Michigan
cited in Who's Who in Science and Engineering, and
Who's Who among U.S. College Teachers
NSF Presidential Young Investigator Award
ONR Young Investigator Award
IBM Faculty Development Award
Trull Centennial Professorship, UT-Austin
General George C. Marshall Scholar, Oxford University
145 invited talks at other institutions, professional meetings, etc
2006-present
2005
2003
2002
2001
2000
1999
1998 - 2000
1996
1993 ff.
1988-1993
1988-1991
1987-1989
1985 - 86
1976-78
1983-present
$312,500
$150,000
$ 60,000
see attached list
1
for one of the two “best papers published in Medical Physics during 2004” (publication #87 on attached list).
for “pioneering contributions to nonlinear and ultrafast laser spectroscopy of solid surfaces and plasmas”
3
for “fundamental contributions to nonlinear and ultrafast laser spectroscopy of solids and surfaces near the melting threshold and of
gases and underdense plasmas near the thresholds of ionization and wakefield generation”
2
Professional Activities
General Chair, Quantum Electronics & Laser Science (QELS ‘05)
Program Chair, Quantum Electronics & Laser Science (QELS ‘03)
Topical Editor, Journal of the Optical Society of America B
*Member, Joint Council for Quantum Electronics (JCQE)
Organized NSF Workshop on Micro/Macroscopic Semiconductor
Interface Characterization
Conference organizing committees: Conference on Lasers & ElectroOptics (CLEO 2000, 1997, 1991); Advanced Accelerator Concepts
Symposium, Working Group Leader (2006, 2004, 2000, 1996)
2005
2003
2000- 2003
2000- 2003
1998
1991-present
*12-member advisory board to promote cooperation among U.S. scientific organization that hold conferences in the field of quantum
electronics & laser science, to organize and operate the 2 largest such conferences (IQEC and QELS), and to represent and advise
their sponsoring organizations.
Inventions
M. C. Downer and P. T. Wilson, “System and Method for Frequency Domain Interferometric Second Harmonic
Spectroscopy,” U.S. Patent 6,411,388 (granted 6-25-02).
M. C. Downer, J. I. Dadap, J. K. Lowell, “Characterization of an external silicon interface using optical second
harmonic generation,” U.S. Patent No. 5,557,409 (granted 9-17-96).
C. W. Siders, E. Gaul, M. C. Downer, “Laser Beam Pointing Stabilizer,” marketed as INLINE TM by Technology
Transfer Corportation, Longwood, FL under consulting agreement with inventors.
Ph.D. Student Supervision (currently supervising 9 Ph.D. candidates)
Bonggu Shim
Ph. D. 2006: Coherently-controlled harmonic generation from exploding noble-gas clusters.
Nicholas Matlis
Ph.D. 2006: Snapshots of laser wakefields using frequency domain holography. Currently
postdoctoral fellow, Lawrence Berkeley National Laboratory (supervisor: W. Leemans)
Jinhee Kwon
Ph.D. 2006: Second-harmonic and reflectance-anisotropy spectroscopy of vicinal Si(001)
interfaces. Currently postdoctoral fellow, Rutgers Univ., NJ (supervisor: Ives Chabal)
Ramon Carriles
Ph.D. 2005: Nonlinear optical characterization of silicon/high-K dielectric interfaces. Currently
postdoctoral fellow, Colorado School of Mines, Golden, CO (supervisor: Jeff Squier)
Kui Wu
Ph.D. 2004: Electric-field-induced second-harmonic microscopy, Currently staff scientist, Wuhan
Telecommunications, China.
Jiang Yingying
Ph.D. 2002: Linear and nonlinear optical spectroscopies of SiGe interfaces and Si nanocrystals.
Postdoctoral fellow, Vanderbilt U. (2003-04); Currently Instructor of Physics, Peking U.
Daeyoung Lim
Ph.D. 2001: Nonlinear optical spectroscopy of silicon-boron and other silicon-adsorbate systems.
Postdoc LANL (2001-03); staff scientist at IBM T. J. Watson Research Center, NY (2003-05);
currently Professor of Physics & Applied Physics, Kyunghee University, Korea.
Erhard W. Gaul
Ph. D. 2000: Production and characterization of a fully-ionized helium plasma channel for high
intensity laser pulse propagation. Laser scientist, Gesellschaft für Schwerionforschung (GSI),
Darmstadt, Germany (2001-04); Currently chief laser scientist, Texas Petawatt project.
Philip T. Wilson*
Ph. D. 2000: Frequency domain interferometric second harmonic spectroscopy. NRC post-doc
at NIST, Gaithersburg, MD; currently research scientist at Milliken Chemical Co., Georgia.
Mikal K. Grimes
Ph. D. 1998: Vacuum heating and expansion of solid surfaces by intense femtosecond laser
irradiation. Currently Senior MTS, Trilogy, Inc., Austin, TX.
Yun-Shik Lee
Ph. D. 1997: Optical fourth harmonic generation at crystalline surfaces. Postdoc, U. Michigan;
currently Assoc. Prof. Physics, Oregon State U.
Xiaofeng Hu
Ph. D. 1997: Femtosecond linear and nonlinear spectroscopy of silicon, germanium and silicongermanium alloys. Senior Member of Technical Staff, Ball Semiconductor, Inc., Dallas, TX
(1997-2000); currently senior MTS at Applied Materials, Inc, Santa Clara, CA.
Craig W. Siders
Ph. D. 1996: An experimental demonstration of the laser wakefield “photon accelerator”:
longitudinal interferometric diagnostics for plasma-based acceleration. Director’s postdoctoral
fellow, Los Alamos National Laboratory (1996-98); Research Faculty Scientist, UC-San Diego
(1998-2000); Asst Prof. of Optics, CREOL, U. Central Florida, Orlando, FL. (2001-05); currently
senior staff scientist, National Ignition Facility, Lawrence Livermore Natl. Laboratory
Jerry Dadap
Ph.D. 1995: Optical second harmonic electro- and thermo-reflectance spectroscopy of
Si(001)/SiO2, H-Si(001), and Si(001)-(2x1) interfaces by femtosecond laser pulses. Postdoctoral
fellow, Physics Dept., Columbia U. (1996-2000); Senior MTS, Tellium, Inc., NJ (2001-04);
Currently Research Scientist, Brookhaven Natl. Laboratory and Columbia University.
Hyeyoung Ahn
Ph.D. 1994: Femtosecond dynamics of condensed matter under planetary interior conditions.
Research Scientist, Nippon Telegraph & Telecommunication (NTT, 1994-96); Research Fellow,
Japan Atomic Energy Research Institute (JAERI, 1996-2000); Research Scientist, Dept. Physics,
National Tsing-Hua U., Taiwan. (2001-05); Currently Prof. of Photonics, Natl, Chiao Tung U.,
Hsinchu, Taiwan
Charlie Wang
Ph.D. 1993: Hydro- and electro-dynamics of solid targets under intense femtosecond laser
excitation. Postdoctoral fellow and Senior Research Scientist, Columbia U. (1993-98). Currently
Senior Development Engineer, Coherent Laser Group, Coherent, Inc., Santa Clara, CA.
Heung Ro Choo
Ph.D. 1992: Rapid scan femtosecond ellipsometry and its application to optical surface
diagnostics and ultrafast carrier dynamics in semiconductors . Senior Researcher, Electronics &
Telecommunications Research Institute (ETRI), Daejon, Korea (1993-2000).
Gary W. Burdick
Ph.D. 1991: Third order contributions to spin-forbidden rare earth optical transition intensities.
Currently Professor of Physics, Andrews University, Michigan.
William M. Wood
Ph.D. 1991: Femtosecond study of plasma generation and dynamics by blueshifting of high
intensity laser pulses. Currently Member of Technical Staff, Los Alamos National Laboratory.
David H. Reitze**
Ph.D. 1990: Femtosecond dynamics of phase transitions in carbon and silicon.
Currently Professor of Physics, U. of Florida (Gainesville).
Glenn B. Focht
Ph.D. 1990: Frequency shifting of femtosecond laser pulses. Deceased.
* winner National Research Council postdoctoral fellowship
** winner of 1991 UT Outstanding Dissertation Award.
M.S. Student Supervision (currently supervising 2 M. S. candidates)
M. S. 2005: Diagnostics for the laser wakefield accelerator
M. S. 2004: Guiding a high energy laser beam through a plasma channel.
M. S. 2003: Time-resolved reflectance-difference spectroscopy of semiconductor interfaces.
M. S. 2002: Optical Parametric Amplifier for Nonlinear Optical Spectroscopy.
M. S. 2001: Propagation of high intensity light through gas-filled hollow-core capillaries.
M. S. 2000: Laser-scanning confocal electric-field-induced second harmonic generation
spectroscopy.
Ralf Büngener
M. S. 1998: Si/Ge epitaxial growth surface monitoring by second harmonic generation.
Stefan Düsterer
M. S. 1998: Second harmonic generation from ferromagnets.
Roland W. Kempf
M. S. 1998: Second, third and fourth harmonic generation at crystalline Si(110) and Si(111)
surfaces.
Christian Fauser
M. S. 1997: Lensing characteristics of a standing acoustic wave in a piezoelectric tube
Mark H. Anderson
M. S. 1997: Fourth harmonic generation from gallium arsenide.
Christoph Trump
M. S. 1996: Femtosecond interferometric study of phase transitions in silicon;
Matthias Goldammer M. S. 1996: Low repetition rate pointing stabilizer for amplified laser systems;
Alexander Frey
M. S. 1994: Repetition rate synchronization of a colliding-pulse mode-locked laser with an
external oscillator
Nelson Turner III
M. S. 1994: Dual beam detection of frequency shifted ultrafast laser pulses.
Sebastian Jung
Alexander Debus
Florian Pollinger
Carsten Winterfeldt
Thomas Pfeiffer
Jesse Canterbury
Undergraduate Student Supervision in Research
James Miller
Brian Mattern
Claudia Treml
Joshua Migliazzo
Hilary Lovett
Mohammed Islam
Afaque Ahmed
Kin Foo Chan
Michael Barber
David Jenkins
Summer 2004. Performed optical second-harmonic experiments on silicon/high K dielectric
interfaces. Supported by NSF REU program. Co-author of publication #94.
Summer 2003. Performed optical second-harmonic experiments on silicon nanocrystals.
Supported by NSF REU program. Co-author of publication #90.
10/99-5/00. Built a Frequency-Resolved Optical Gating (FROG) device for characterizing
femtosecond laser pulses. Pursued graduate work at U. Würzburg, Germany.
9/97-6/99. Developed commercial laser beam pointing stabilizer device (supported by Texas
Advanced Technology Program). Earned graduate degree at Ecole Polytechnique.
Summers 1997, 1998. Developed interferometric system for characterizing femtosecond
pulses; developed femtosecond laser micromachining technique. Pursued graduate
environmental engineering program.
1/96-8/96. Assisted with nonlinear optical experiments (supported by R. A. Welch Foundation).
Earned Ph.D. in physics at U. California-Berkeley.
1/93- 9/95. Developed and maintained data acquisition system for in-situ optical second
harmonic measurements (supported by Welch Foundation). Earned M.B.A. at McMaster U.
9/95-1/96. Performed optical second harmonic experiments on MOS structures. Earned Ph.D.
in Biomedical Engineering, UT-Austin.
Summer 1994. Assisted with in-situ optical second harmonic experiments (supported by NSF)
Summer 1990. Helped construct a Ti:S femtosecond laser (supported by NSF Research
Experiences for Undergraduates Program). Earned Ph.D. in physics at U. Maryland.
Postdoctoral Supervision
Y. Q. An
A. Rundquist
L. Mantese
Z. Xu
S. P. LeBlanc
D. M. Riffe
W. C. Banyai
T. R. Zhang
2004-present
1998-2000
1998- 2000
1996-1997
1995-1999
1991-1994
1989-1991
1986-1988
Ph.D. U. Colorado
Ph.D. U. Michigan
Ph.D. NCSU
Ph.D. U. Rochester
Ph.D. Rice U
Ph.D. Cornell U.
Ph.D. U. Arizona
Ph.D. U. Texas
currently Assoc. Prof. of Physics, Hamline U., Minnesota
currently MTS, Agilent, Inc, Santa Clara, CA
currently MTS, Applied Materials, Inc, Santa Clara, CA
current senior research scientist, 3M Corporation, Austin, TX
currently Prof. of Physics, Utah State U., Logan, UT
currently senior research scientist, Stanford University, CA
currently MTS, Compact Software, Inc., Paterson, NJ
CAREER RESEARCH HIGHLIGHTS (reference numbers from publication list)
• Two-photon laser spectroscopy of rare earth ions
[publications 1, 4, 5, 6, 15, 18 & two book chapters; 430 citations as of 3/06]
In Ph.D. work during the 1980s, Downer pioneered the field of experimental two-photon spectroscopy of 4f4f transitions in lanthanide-doped crystals [1,4-6], an important class of solid-state laser media. Building on
earlier theoretical work by B. R. Judd and B. G. Wybourne, he advanced a new class of 3rd and higher order
“Wybourne-Downer mechanisms” [4,5,15,18] which accounted quantitatively for widespread anomalies in
both two-photon and linear spectroscopy of lanthanides, which has provided a widely-cited foundation for
both experimental and theoretical work in this field since the mid-1980s.
• High-intensity laser-solid interactions: melting, hydrodynamic surface expansion, electron & x-ray
emission, vacuum heating, ballistic hot electron transport
[publications 9,12,17,19, 20, 22, 25, 26, 28, 31, 32, 34, 37, 62, 99, 100 & one book chapter; 540
citations as of 3/06]
Downer led several key experiments which defined the ultrafast heating and melting physics of solid target
surfaces [9-12,19,20,22,26,28,31,32,34,37]. He made the first femtosecond (fs) “movie” of the melting and
plasma expansion of fs-irradiated silicon [9]. He demonstrated ultrafast melting of elemental carbon for the
first time [19,22,26], then provided the first quantitative measurements of the temperature-dependent optical
properties of the elusive liquid state of carbon [26,31], exploiting the well-defined surface of the transient
sample during the first half-picosecond following excitation. These measurements stimulated new molecular
dynamics simulations of the liquid state, and have astro- and geo-physical implications. Using innovative
techniques based on ultrafast thin film interference [12] and ultrafast thermionic electron emission [32,37],
Downer first demonstrated the significant role of Auger processes [12] and temperature-dependent electronphonon coupling [37] in governing heat transfer from carrier to lattice systems under ultrafast melting
conditions, thus defining important differences from both lower and higher intensity regimes. Downer's group
first experimentally identified "vacuum heating" [62] predicted by Brunel in 1987, in which light is absorbed
by drawing electrons into vacuum and returning them to the target with the quiver velocity. In current work,
Downer's group re-visits "fs imaging" [9] with relativistically intense pump pulses, to measure nonlocal
radiative and hot electron transport in solid density plasmas [99]. These experiments provide input for codes
used to analyze fast ignition of laser fusion, proton and ion beam generation, and astrophysics.
• High-intensity laser interactions with gases & underdense plasmas: ionization blue-shifts, laser
wakefield characterization, plasma channels, laser-cluster interactions
[publications 16, 24, 27, 29, 30, 36, 39-42, 45-47, 51, 54, 59, 60, 66, 71, 72, 74, 86-89, 102-104; 750
citations as of 3/06]
During the early 1990s, when unique features of intense-field atomic ionization were first coming to light,
Downer performed the first fs-time-resolved experiments on ionizing gases using ionization-induced spectral
blue-shifting [16,24,27,29,30,42,51,72,88]. In addition to fs-time-resolution, these experiments accessed
higher gas densities than electron and ion detection experiments, thus probing high-intensity collisional
physics for the first time. This widely cited work continues to impact research into propagation of intense
short pulses through dense gases, as in the fast ignitor project. In the mid-1990s, Downer’s group
pioneered fs-time-resolved experiments diagnosing laser wakefields [45,46,47,54,71,102] both in the lowdensity resonantly-driven regime using frequency-domain interferometry [45,46], and in the high-density
forward Raman instability-driven regime, using collective Thomson scattering [47,60]. Recently his group
has obtained the first holographic snapshots of laser wakefields [102] using frequency-domain holography, a
single-shot extension of frequency-domain interferometry developed by Downer’s group [71]. To extend
high-intensity interaction lengths to ≥1 cm, Downer's group improved on a plasma fiber technique developed
by H. M. Milchberg, demonstrating distortion-free guiding of laser pulses with 0.2 x 1018 W/cm 2 peak intensity
through 1.5 cm-long fully-ionized He plasma channels [74], and performing the first pump-probe experiments
in such a channel [88]. His group developed the theory of Raman-seeded wakefield acceleration [89], a
path to controlled, high-repetition rate production of MeV electron beams for medical applications [86,87],
and developed a two-color terawatt laser system [104] for experiments. Recently he has demonstrated
enhanced harmonic generation in exploding noble-gas clusters using a pump-probe scheme [103].
• Nonlinear optical spectroscopy of surface & interfaces
[publications 33, 35, 43, 44, 48-50, 52, 53, 55-58, 61, 63, 65, 67-70, 73, 75, 76, 78-80, 82-85, 90-98,
101; 490 citations as of 3/06]
Downer pioneered the application of widely tunable fs sources to even-order nonlinear spectroscopy of
semiconductor surfaces [35,43,44,50,52,53,55-58,63-65,67-70,73,75,76,78-80], simultaneously advancing
spectroscopic fundamentals [50,68,70,76,78,79], applications to semiconductor manufacturing [35,44,53,56],
and spectroscopic techniques [55,58,65]. His contributions include: first quantitative characterization of
angstrom-scale roughness at a buried interface (Si/SiO 2) based on optical second harmonic generation (SHG)
[35, U.S. Patent 6,411,388]; first SHG spectroscopy of a metal-oxide-semiconductor (MOS) structure [44,83],
leading to the most complete theoretical description of electric-field-induced SHG, or EFISH [48,49,61]; first
quantitative, real-time, in-situ SHG-based measurements of kinetics of chemical vapor deposition growth of
silicon and germanium films [43,50,53,56,57,63,69]; the first demonstration of 4th harmonic spectroscopy
from crystalline surfaces below melting threshold [55,58,67]; first SHG spectroscopy of silicon nano-interfaces
[75,80] including development of a novel two-beam SHG method for enhancing quadrupolar nano-interface
response [90,91,97]; invention of frequency-domain interferometric second-harmonic (FDISH) spectroscopy
[65,82,95, U.S. Patent 6,411,388]; first quantitative comparison of SHG and reflectance-anisotropy
spectroscopy (RAS) on common (vicinal Si) surfaces [85,93,96]; first SHG spectroscopy of Si/high-K dielectric
interfaces [94,101].
Named Physical Effect
M. Tanaka and T. Kushida, “Interference between Judd-Ofelt and Wybourne-Downer mechanisms in the 5D0 - 7F J
transitions of Sm2+ in solids, “ Journal of Chemical Physics 53, 588 (1996). The “Wybourne-Downer mechanisms”
cited in the title of this recent paper were first introduced by me and UT graduate student Gary Burdick in two J.
Chem. Phys. paper in 1988,89 (see #23, 27 on publication list).
Recent Newsbrief Articles
“Two-Beam Second-Harmonic Generation”, by L. Sun, S. Cattaneo, P. Figliozzi, Y. Jiang, Y. Q. An, W. L. Mochán, B.
S. Mendoza, M. Kauranen, and M. C. DOWNER, in Optics & Photonics News, p. 34 (Dec. 2005). Special
year-end issue devoted to “Optics Highlights of 2005”.
“Ultrafast radial transport in micro-size laser-produced plasmas,” in Petawatters No. 8 (2005) – Newsletter of the
Institute for Laser Energetics (ILE), Osaka, Japan.
“New Light from Silicon Nano-Interfaces,” in Texas Materials Institute Bulletin, Winter 2005.
“Stardust to Semiconductors,” in Focus on Science, Summer 2000.
Billy Goodman, “Star in a Bottle,” Air & Space, February/March 1998.
J. Glanz, “Meeting takes pulse of laser accelerators,” Science 271, 26 (1996).
C. Joshi and P. Corkum, “Interactions of ultra-intense laser light with matter,” Physics Today 48, 36 (1995).
N. Bloembergen, “First light on fluid carbon,” Nature 356, 110 (1992). New & Views article about publication #26.
SUMMARY OF CURRENT RESEARCH (reference numbers from publication list)
1) High-intensity laser-plasma interactions
a) Laser wakefield acceleration (primary financial support: Dept. of Energy)
Diagnostics: We measure transverse and longitudinal structure of laser-generated wakefields in a single
laser shot [102], using the technique of frequency domain holography [71]. We resolve wave front curvature
seen previously only in simulations, and reconstruct and display wake morphology from raw data within
seconds, providing real-time feedback for experimental optimization between laser shots. Such snapshots
open a direct window into intense laser-plasma physics. Plasma “bubbles” and fast-ignitor tracks should be
similarly observable. (1 Ph. D. student)
Raman Seeding: Conventional laser wakefield accelerators operate at low laser repetition rate (≤ 10 Hz),
whereas most applications demand kilohertz repetition rates to achieve µA average current. Using particlein-cell simulations, we developed the concept of “seeding” the forward Raman scattering instability by
supplementing the main driving pulse with a weak (1%) co-propagating pulse shifted by the plasma
frequency ωp [89]. Analogous to injection seeding of Raman amplifier, the seed suppresses noise and
reduces driving pulse energy, enabling higher repetition rate. Simulated electron yield is promising for
medical applications [86, 87]. A two-color terawatt chirped-pulse laser system has been developed [104] to
implement experimental demonstration of Raman-seeded laser-wakefield acceleration. (2 Ph. D. students}
Channeling: Distortion-free propagation of TW pulses through 1.5 cm long low Z plasma channels [74], and
frequency-domain interferometric pump-probe experiments [88] have been demonstrated. Low Z channels
are now being generated in a differentially-pumped cell, enabling efficient coupling of 5 TW pulses and
generation of channeled laser wakefields. (1 Ph. D. student)
b) Laser-solid interactions (primary financial support: NSF FOCUS Center)
Harmonic generation in exploding clusters: Several years ago we predicted that harmonic generation from
clustered plasma would become phase-matched at a critical cluster size and density [66]. We recently
performed pump-probe experiments that confirm the predicted enhancement in third-harmonic generation
[103], while revealing new subtleties caused by competition among time-varying phase-matching, resonant
enhancement of the nonlinear cluster susceptibility χ(3) and linear absorption during cluster expansion. The
enhancement mechanism is being scaled to generation of high-harmonics into the soft x-ray regime. (1 Ph.
D. student)
Nonlocal energy transport in solid density plasmas: Using fs microscopy [9] and x-ray imaging, we observe
subpicosecond transport of thermal energy radially outward from micrometer-sized spot of low-Z and high-Z
solid targets following relativistically intense fs excitation [99]. In this excitation regime, thermal plasma
electrons reach ≥ 1 keV temperature, and much deposited energy channels into superthermal (tens of keV)
electrons. Thus radiation and hot electrons become dominant carriers of energy out of the initially
photoexcited volume. Results are being used to test particle-in-cell simulations of hot electron transport in
self-generated mega-gauss magnetic fields, and theoretical models of radiative transport. The physics of
this transport is relevant to fast ignition of laser fusion, generation of ultrashort x-rays and relativistic proton
and ion beams, and to astrophysics. (1 Ph. D. student)
2) Optical second-harmomic spectroscopy of semiconductor nano-interfaces (financial support:
NSF-DMR, Robert Welch Foundation)
SHG spectroscopy of interfaces of embedded Si nano-crystals: Si nano-crystals embedded in glass behave
in a most un-silicon-like manner: they glow brightly, a feature giving birth to Si light-emitting devices, maybe
lasers. Unusualy bonding structures at the nanocrystal-glass interfaces are believed responsible, but
effective experimental probes have eluded the surface scientist. We demonstrated that optical secondharmonic generation (SHG), a noninvasive spectroscopic probe of planar interfaces, is sensitive to these
nano-interfaces [75, 80, 90, 97]. We invented a novel two-beam SHG configuration that generates a robust
SH beam that is sensitive to chemical modification of the nano-interfaces [90,91,97]. Current experiments
use tunable pulses, and pump-probe techniques, to measure the spectrum and lifetime of nano-interface
states to elucidate their poorly understood electronic structure. (2 Ph. D. students, 1 postdoc)
SHG and RAS of step-edges at vicinal Si surfaces: Step-edges at vicinal Si interfaces provide templates for
growth of nano-wires, unique chemistry to control step-flow epitaxial growth, and unique electrical properties
to control local fields, channel mobility and breakdown in opto-electronic devices. They also provide a
unique context for directly comparing the two most important optical surface spectroscopies: secondharmonic generation (SHG) and reflectance-anisotropy spectroscopy (RAS) for the first time. We have
made a direct experimental comparison of RAS and spectroscopic SHG of native-oxidized [85,93] and clean,
reconstructed [96] Si(001) and discovered a common microscopic origin of RAS and SHG by analyzing both
spectra with a simplified bond hyperpolarizability model (1 Ph. D. student).
Current Research Grants
M.C. Downer
M. C. Downer
M.C. Downer
M. C. Downer
M. C. Downer
Department of Energy1
National Science Foundation2
Robert A. Welch Foundation3
National Science Foundation4
Sematech5
1/15/05 - 1/14/08
8/1/01-7/31/07
6/1/04 - 5/31/07
9/1/02 - 8/31/06
9/1/04 – 8/31/05
$650,000
$700,000
$150,000
$365,000
$100,000
1 "Laser wakefield acceleration: channeling, seeding and diagnostics"
2
”Frontiers in Optical Coherent & Ultrafast Science (FOCUS)” (PH Bucksbaum, director)
nonlinear optical probes of Column IV interface chemistry"
4
“Nonlinear spectroscopy of planar and nanocrystalline silicon interfaces: experiments for ab initio theory”
5
"Optical characterization of silicon high-K dielectric interfaces”
3 "Femtosecond
TEACHING HIGHLIGHTS
1) Interactive teaching. Introduced "Concept Quiz" procedure, an interactive teaching method which
encourages dialog between lecturer and students, and among students, in a large lower division
classroom setting such as PHY 316, PHY 303L, or PHY 302L. This procedure was subsequently
adopted by several other faculty (Chiu, Moore, Kleinman), was computerized as part of the Painter
Hall lecture room remodeling, and has become a standard departmental procedure for large
introductory lecture courses. In Fall & Spring 2002 and Spring 2004 semesters I introduced Concept
Quizzes for the first time into Upper Division Course PHY 352K: Classical Electrodynamics. I
composed and field-tested approximately 40 new concept quizzes, and found them to be an effective,
well-received teaching tool at the advanced undergraduate physics major level.
2) New graduate course. Proposed, designed, and six times taught the graduate Advanced Course
PHY 395K: "Nonlinear Optics and Lasers" on behalf of the Atomic & Molecular Physics group.
Enrollment has exceeded 20 on every offering, and 30 on some. I will teaching this course for the
seventh time in Fall 2006.
3) Laboratory course improvements. Introduced a substantial expository writing and public speaking into
undergraduate (PHY 474) and graduate (PHY 380N) laboratory courses. Initiated 4 new experiments
- high Tc superconductors, holography, diode laser spectroscopy, and an optical fiber experiment - in
the advanced undergraduate laboratory PHY 474.
4) Undergraduates in research. Supervised and financially supported the work of 10 undergraduate
students in my research program over the last 8 years. These included James Miller and Brian
Mattern in the past 2 years, both of whom co-authored publications [Papers 90, 94 on publication
list], made presentations on their work at the UT College of Natural Sciences (CNS)
undergraduate research symposium, and have gone on to graduate scientific work. During most
semesters when PHY 380N has been offered, supervised the semester-long research projects of 1 or
2 PHY 380N students working in my laboratory.
5) CIR-KITS. Initiated and developed a flexible inventory of low-cost “CIr-Kits” (take-home electrical
circuit kits) with accompanying homework assignments for use in introductory Electricity & Magnetism
courses. The contents of the kits fit in a small sandwich bag, and can be worked on in a student’s
apartment, at the library, in the hallway, at the coaching tables, or in the cafeteria. I used Cir-Kits with
50 to 85 students in 6 different semesters in PHY 316 and PHY 302L classes starting in fall 97. With
the help of a Dean’s Fellowship for Curriculum Development (spring 99), I expanded and streamlined
the Cir-Kits with the aim of developing a standard Departmental procedure which could ultimately be
used in the Physics Department’s 302L, 303L, 309L, 316, and 317L introductory E&M courses.
Student Advising
Faculty Advisor and co-founder of Texas Optics Society, a new UT student chapter of the Optical Society of America
(OSA) and the International Society for Optical Engineering (SPIE). This organization sponsors faculty and student
seminars and social events involving UT optics researchers in the Colleges of Natural Science and Engineering.
Web site: http://www.engr.utexas.edu/texasoptics/
UT Physics Department Service
Member, Undergraduate Committee, 2002-present
Member, faculty recruitment committee; played central role in recruitment of T. Ditmire (2000) & G. Shvets (2003).
Chairman, Budget Council Advisory Committee (BCAC), 1993-94; Member, BCAC, 1991-94, 1995-98
GRACL (GRaduate Academic CurricuLum committee), 1990-91
page 1
citation count
from ISI Web
of Science
Refereeed Journal Publications
key to roles:
updated 1/3/08
group leader and P. I. = A
primary junior researcher = B
essential collaborator = C
peripheral collaborator = D
role
citations #
67
1
M. Dagenais, M. DOWNER, R. Neumann, and N. Bloembergen, “Two-photon absorption as a new test of the
Judd-Ofelt theory.” Physical Review Letters 46, 561-565 (1981).
C
51
2
A. Bogdan, M. DOWNER, and N. Bloembergen, “Quantitative characteristics of pressure-induced degenerate
frequency resonance in four wave mixing.” Optics Letters 6, 348-350 (1981).
C
54
3
A. Bogdan, M. DOWNER, and N. Bloembergen, “Quantitative characteristics of pressure- induced four wave
mixing signals observed with cw laser beams.” Physical Review A 24, 623-626 (1981).
C
53
4
M.C. DOWNER, A. Bivas, and N. Bloembergen, “Selection rule violation, anisotropy, and anomalous intensity
of two-photon absorption lines in Gd3+: LaF3.” Optics Communications 41, 335-339 (1982).
B
110
5
M.C. DOWNER and A. Bivas, “Third and fourth order analysis of the intensities and polarization dependence
of two-photon absorption lines of Gd3+ in LaF3 and aqueous solution.” Physical Review B 28, 3677-3696
(1983).
B
82
6
M.C. DOWNER, C.D. Cordero-Montalvo, and H. Crosswhite, “Study of new 4f7 levels of Eu2+ in CaF2 and
SrF2 using two-photon absorption spectroscopy.” Physical Review B 28, 4931-4943 (1983).
B
191
7
W.H. Knox, M.C. DOWNER, R.L. Fork, and C.V. Shank, “Amplified femtosecond optical pulses and
continuum generation at 5 KHz repetition rate.” Optics Letters 9, 552-554 (1984).
C
91
8
M.C. DOWNER, R.L. Fork, and C.V. Shank, “Femtosecond imaging of melting and evaporation at a photoexcited silicon surface.” Journal of the Optical Society of America B 2, 595-599 (1985).
B
204
9
W.H. Knox, R.L. Fork, M.C. DOWNER, D.A.B. Miller, D.S. Chemla, C.V. Shank, A.C. Gossard, and W.
Wiegmann, “Femtosecond dynamics of resonantly generated excitons in room temperature GaAs quantum
wells.” Physical Review Letters 54, 1306-1309 (1985).
C
180
10 W.H. Knox, R.L. Fork, M.C. DOWNER, R.H. Stolen, C.V. Shank, and J. Valdmanis, “Optical pulse
compression to 8 femtoseconds at a 5 KHz repetition rate.” Applied Physics Letters 46, 1120-1121 (1985).
C
77
11 M.C. DOWNER and C.V. Shank, “Ultrafast heating of silicon-on-sapphire by femtosecond optical pulses.”
Physical Review Letters 56, 761-764 (1986).
B
16
12 G. Focht and M.C. DOWNER, “Generation of synchronized ultraviolet and red femtosecond pulses by
intracavity frequency doubling.” IEEE Journal of Quantum Electronics 24, 431-434 (1988).
A
6
13 T.R. Zhang, G. Focht, P.E. Williams, and M.C. DOWNER, “Theory of intracavity frequency doubling in
passively mode-locked femtosecond lasers.” IEEE Journal of Quantum Electronics 24, 1877-1883 (1988).
A
52
14 M. C. DOWNER, G. W. Burdick, and D. K. Sardar, “A new contribution to spin-forbidden rare earth optical
transition intensities: Gd3+ and Eu3+.” Journal of Chemical Physics 89, 1787-1797 (1988).
A
49
15 W.M. Wood, G. Focht, and M.C. DOWNER, “Tight focusing and blue shifting of millijoule femtosecond pulses
from a conical axicon amplifier.” Optics Letters 13, 984-986 (1988).
A
31
16 O.R. Wood II, W.T. Silfvast, H.W.K. Tom, W.H. Knox, R.L. Fork, C.H. Brito-Cruz, M.C. DOWNER, and P.J.
Maloney, “Effect of laser pulse duration on XUV emission from femtosecond and picosecond laser-produced
Ta plasmas.” Applied Physics Letters 53, 654-656 (1988).
C
33
17 G.W. Burdick, M.C. DOWNER, and D.K. Sardar, “A new contribution to spin-forbidden rare earth optical
transition intensities: analysis of all trivalent lanthanides.” Journal of Chemical Physics 91, 1511- 1520
(1989).
A
page 2
Refereeed Journal Publications
updated 1/3/08
27
18 D.H. Reitze, X. Wang, H. Ahn, and M.C. DOWNER, “Femtosecond laser melting of graphite.” Physical
Review. B 40, 11986-11989 (1989).
A
40
19 D.H. Reitze, T.R. Zhang, W.M. Wood, and M.C. DOWNER, “Two-photon spectroscopy of silicon using
femtosecond pulses at above gap frequencies.” Journal of the Optical Society of America B 7, 84-89 (1990).
A
43
20 T.R. Zhang, H.R. Choo, and M.C. DOWNER, “Phase and group velocity matching for second harmonic
generation of femtosecond pulses.” Applied Optics 29, 3926-3933 (1990).
A
32
21 K. Seibert, G.C. Cho, W. Kütt, H. Kurz, M.C. DOWNER, D.H. Reitze, J. Dadap, and A.M. Malvezzi,
“Femtosecond carrier dynamics in graphite.” PhysIcal Review B 42, 2842-2851 (1990).
22 G.W. Burdick and M. C. DOWNER, ‘The role of linear crystal field terms in hypersensitive Eu3+ optical
transition intensities.’ Eur. J. Solid State Inorganic Chem. 28, 217-220 (1990).
23 M. C. DOWNER, W.M. Wood, and J.I. Trisnadi, “Comment on 'Energy Conservation in the Picosecond and
Subpicosecond Photoelectric Effect'.” Physical Review Letters 65, 2832 (1990).
A
37
24 J.I. Dadap, D.H. Reitze, G.B. Focht, and M.C. DOWNER, “Autocorrelation measurement of ultraviolet
femtosecond pulsewidths by two-photon absorption in diamond.” Optics Letters 16, 499-502 (1991).
A
77
25 D. H. Reitze, H. Ahn, and M. C. DOWNER, “Optical properties of liquid carbon measured by femtosecond
spectroscopy. “ Physical Review B 45, 2677-2693 (1992).
A
118
26 W. M. Wood, C. W. Siders, and M. C. DOWNER, “Measurement of femtosecond ionization dynamics of
atmospheric density gases by spectral blueshifting.” Physical Review Letters 67, 3523-3526 (1991).
A
40
27 X. Y. Wang and M. C. DOWNER, "Femtosecond time-resolved reflectivity of hydrodynamically expanding
metal surfaces." Optics Letters 17, 1450-1452 (1992).
A
37
28 B. I. Penetrante, N. M. Bardsley, W. M. Wood, C. W. Siders, and M. C. DOWNER, "Ionization-induced
frequency shifts in intense femtosecond laser pulses." Journal of the Optical Society of America B 9, 20322040 (1992).
A
42
29 W. M. Wood, C. W. Siders, and M. C. DOWNER, "Femtosecond growth dynamics of an underdense
ionization front measured by spectral blueshifting." IEEE Transactions on Plasma Science 21, 20-33 (1993).
A
4
30 M. C. DOWNER, H. Ahn, D. H. Reitze, and X. Y. Wang, "Dielectric function and electrical resistivity of liquid
carbon determined by femtosecond spectroscopy." International Journal of Thermophysics 14, 361-370
(1993).
A
28
31 D. M. Riffe, X. Y. Wang, M. C. DOWNER, D. L. Fisher, T. Tajima, J. L. Erskine, and R. M. More,
"Femtosecond thermionic emission from metals in the space-charge-limited regime." Journal of the Optical
Society of America B 10, 1424-1435 (1993).
32 H. R. Choo, X. F. Hu, M. C. DOWNER, and V. P. Kesan, "Femtosecond ellipsometric study of nonequilibrium
carrier dynamics in Ge and epitaxial Si1-xGex." Applied Physics Letters 63, 1507-1509 (1993).
A
21
33 T. Dallas, M. Holtz, H. Ahn, and M. C. DOWNER, "Structural phase of femtosecond laser melted graphite."
Physical Review B 49, 796-801 (1994).
C
51
34 J. I. Dadap, B. Doris, Q. Deng, M. C. DOWNER, J. K. Lowell, and A. C. Diebold, "Randomly-oriented
angstrom-scale microroughness at the Si(100)/SiO2 interface probed by optical second harmonic
generation." Applied Physics Letters 64, 2139-2141 (1994).
A
16
35 E. V. Vanin, A. V. Kim, A. M. Sergeev, and M. C. DOWNER, "Excitation of ultrashort bursts of harmonics of
the radiation during ionization of a gas by an intense light pulse." Pis'ma Zh. Eksp. Teor. Fiz. 58, 964-969
(1993) [JETP Letters 58, 900-906 (1994)].
36 X. Y. Wang, D. M. Riffe, Y. S. Lee, and M. C. DOWNER, "Time-resolved electron temperature measurement
in a highly excited gold target using femtosecond thermionic emission," Physical Review B 50, 8016-8019
(1994).
A
37 C. W. Siders, E. Gaul, M. C. DOWNER, A. Babine, A. Stepanov, "Self-starting femtosecond pulse
generation from a Ti: sapphire laser synchronously pumped by a pointing-stabilized mode-locked Nd: YAG
laser," Review of Scientific Instruments 65, 3140-3144 (1994).
A
6
19
16
90
14
A
A
A
A
page 3
Refereeed Journal Publications
updated 1/3/08
4
38 D. L. Fisher, T. Tajima, M. C. DOWNER, and C. W. Siders, “Envelope evolution of a laser pulse in an active
medium,” Physical Review E 51, 4860-4868 (1995).
D
18
39 K. Nakajima, T. Kawakubo, H. Nakanishi, A. Ogata, Y. Kato, Y. Kitagawa, R. Kodama, K. Mima, H. Shiraga, K.
Suzuki, T. Zhang, Y. Sakawa, T. Shoji, Y. Nishida, N. Yugami, M. C. DOWNER, D. Fisher, B. Newberger, and
T. Tajima) “A proof-of-principle experiment of laser wakefield acceleration,” Physica Scripta T52, 61-64
(1994).
C
225
40 K. Nakajima, D. L. Fisher, T. Kawakubo, H. Nakanishi, A. Ogata, Y. Kato, Y. Kitagawa, R. Kodama, K. Mima,
H. Shiraga, K. Suzuki, K. Yamakawa, T. Zhang, Y. Sakawa, T. Shoji, Y. Nishida, N. Yugami, M. C. DOWNER,
T. Tajima, “Observation of ultrahigh gradient electron acceleration by a self-modulated intense short laser
pulse.” Physical Review Letters 74, 4428-4431 (1995).
C
35
41 C. W. Siders, N. C. Turner III, M. C. DOWNER, A. Babine, A. Stepanov, and A. Sergeev, “Blueshifted third
harmonic generation during ultrafast barrier suppression ionization of subatmospheric density noble gases.”
Journal of the Optical Society of America B 13, 330-335 (1996).
A
24
42 J. I. Dadap, X. F. Hu, N. M. Russell, J. G. Ekerdt, M. C. DOWNER, and J. K. Lowell, “Analysis of second
harmonic generation by unamplified, high repetition rate ultrashort laser pulses at Si(001) interfaces.” IEEE
Journal of Special Topics in Quantum Electronics 1, 1145-1155 (1995).
A
67
43 J. I. Dadap, X. F. Hu, M. Anderson, M. C. DOWNER, J. K. Lowell, and O. A. Aktsipetrov, “Optical second
harmonic spectroscopy of a Si(001) metal-oxide-semiconductor structure,” Physical Review B 53, R76077609 (1996).
A
15
44 C.W. Siders, S. P. Le Blanc, T. Tajima, M. C. DOWNER, A. Babine, A. Stepanov, and A. M. Sergeev, “Plasmabased accelerator diagnostics based upon longitudinal interferometry with ultrashort optical pulses,” IEEE
Transactions on Plasma Science 24, 301-315 (1996).
A
83
45 C.W. Siders, S. P. Le Blanc, T. Tajima, M. C. DOWNER, A. Babine, A. Stepanov, and A. M. Sergeev, “Laser
Wakefield excitation and measurement by femtosecond longitudinal interferometry,” Physical Review Letters
76, 3570-3573 (1996).
A
57
46 S. P. Le Blanc, M. C. DOWNER, R. Wagner, S.Y. Chen, A. Maksimchuk, G. Mourou, and D. Umstadter,
“Characterization of a self-modulated laser wakefield by time-resolved Thomson scattering,” Physical Review
Letters 77, 5381-5384 (1996).
A
13
47 O. Aktsipetrov, A. Fedyanin, and M. C. DOWNER, ‘DC-electric-field-induced second harmonic generation
studies of surfaces and buried interfaces of Column IV semiconductors,” Laser Physics 6, 1142-1151 (1996).
C
13
48 O. Aktsipetrov, A. Fedyanin, V. Melnikov, J I. Dadap, X. F. Hu, M. Anderson, M. C. DOWNER, J. K. Lowell,
“Optical second harmonic electroreflectance spectroscopy of the Si(001)-SiO2 interface in Si-SiO2-Cr MOS
structures: separation of the surface and bulk nonlinear contributions,” Thin Solid Films 294, 231-234 (1997).
C
51
49 J. I. Dadap, N. M. Russell, X. F. Hu, O. A. Aktsipetrov, J. G. Ekerdt, and M. C. DOWNER, “Second harmonic
spectroscopy of a Si(001) surface during calibrated variations in temperature and hydrogen coverage,”
Physical Review B 56, 13367-13379 (1997).
A
7
50 B. Rau, C. W. Siders, S. P. Le Blanc, D. L. Fisher, M. C. DOWNER, T. Tajima, “Spectroscopy of short, intense
laser pulses due to gas ionization effects,” Journal of the Optical Society of America B 14, 643-649 (1997).
C
30
51 J. I. Dadap, P. T. Wilson, M. ter Beek, M. H. Anderson, and M. C. DOWNER, “Femtosecond carrier-induced
screening of dc-electric field-induced second harmonic generation at the Si(001)/SiO2 interface,” Optics
Letters 22, 901-903 (1997).
52 Z. Xu, X. F. Hu, D. Lim, J. G. Ekerdt, and M. C. DOWNER, “Second harmonic spectroscopy of Si(001)
surfaces: sensitivity to surface hydrogen and doping, and applications to kinetic measurements,” Journal of
Vacuum Science and Technology B 15, 1059-1064 (1997).
A
18
A
page 4
Refereeed Journal Publications
updated 1/3/08
11
53 C. W. Siders, A. J. Taylor, and M. C. DOWNER, “Multi-pulse interferometric frequency resolved optical gating:
real-time phase-sensitive imaging of ultrafast dynamics,” Optics Letters 22, 624-626 (1997).
C
9
54 Y. S. Lee, M. H. Anderson, and M. C. DOWNER, “Fourth harmonic generation at a crystalline GaAs(001)
surface,” Optics Letters 22, 973-975 (1997).
A
27
55 X. F. Hu, Z. Xu, D. Lim, M. C. DOWNER, P. S. Parkinson, B. Gong, G. Hess, J. G. Ekerdt, “In situ optical
second harmonic generation monitoring of disilane adsorption & hydrogen desorption during Si(001) epitaxial
growth,” Applied Physics Letters 71, 1376-1378 (1997).
A
12
56 G. Hess, P. Parkinson, B. Gong, Z. Xu, D. Lim, M. C. DOWNER, S. John, S. Banerjee, J. G. Ekerdt, and S. K.
Jo, “Evolution of subsurface hydrogen from boron-doped Si(100),” Applied Physics Letters 71, 2184-2186
(1997).
C
9
57 Y. S. Lee and M. C. DOWNER, “Reflected fourth harmonic radiation from a centrosymmetric crystal,” Optics
Letters 23, 918-920 (1998).
A
2
58 C. M. Fauser, E. Gaul, S. P. Le Blanc, and M. C. DOWNER, “Optical guiding characteristics of a standing
acoustic wave in a piezoelectric cylinder,” Applied Physics Letters 73, 2902-2904 (1998).
A
2
59 J. Koga, S. Kato, Y. Kishimoto, S. P. Le Blanc, and M. C. DOWNER, “Optical field ionization effects on the
generation of wakefields with short pulse lasers,” Nuclear Instruments and Methods in Physics Research A
410, 499-504 (1998).
A
27
60 O. A. Aktsipetrov, A. A. Fedyanin, A. V. Milnikov, E. D. Mishina, A. N. Rubtsov, M. H. Anderson, P. T. Wilson,
M. ter Beek, X. F. Hu, J. I. Dadap, and M. C. Downer, “DC-electric-field-induced and low-frequency
electromodulation second-harmonic generation spectroscopy of the Si(001)-SiO2 interface,” Physical Review
B 60, 8924-8938 (1999).
61 M. K. Grimes, A. R. Rundquist, Y.-S. Lee, and M. C. DOWNER, “Experimental identification of vacuum
heating at femtosecond-laser-irradiated metal surfaces,” Physical Review Letters 82, 4010-4013 (1999).
C
12
62 P. S. Parkinson, D. Lim, R. Büngener, M. C. DOWNER, and J. G. Ekerdt, “Second harmonic spectroscopy of
Ge/Si(001) and Si1-xGex(001)/Si(001),” Applied Physics B 68, 641-648 (1999).
A
8
63 R. Kempf, P. T. Wilson, M. C. DOWNER, E. Mishina, O. A. Aktsipetrov, “Third and fourth harmonic generation
from Si-SiO2 interfaces and in Si-SiO2-Cr MOS structures,” Applied Physics B 68, 325-332 (1999).
A
30
64 P. T. Wilson, Y. Jiang, O. Aktsipetrov, E. Mishina, M. C. DOWNER, “Frequency domain interferometric second
harmonic spectroscopy,” Optics Letters 24, 496-498 (1999).
A
24
65 T. Tajima, Y. Kishimoto, and M. C. DOWNER, “Optical properties of clustered plasma,” Physics of Plasmas 6,
3759-3764 (1999).
C
2
66 Y. –S. Lee and M. C. DOWNER, “Reflected optical fourth harmonic generation at crystalline surfaces,” Thin
Solid Films 364, 80-85 (2000).
A
14
67 V. I. Gavrilenko. R. Q. Wu, M. C. DOWNER, J. G. Ekerdt, D. Lim, P. Parkinson, “Optical second harmonic
spectra of silicon ad-atom surfaces: theory and experiment,” Thin Solid Films 364, 1-5 (2000).
C
5
68 L. Mantese, K. Selinidis, P.T. Wilson, D. Lim, Y.Y. Jiang, J. G. Ekerdt, M. C. DOWNER, “In-situ control and
monitoring of doped and compositionally-graded SiGe films using spectroscopic ellipsometry and second
harmonic generation,” Applied Surface Science 154-155, 229-237 (2000).
A
28
69 D. Lim, M. C. DOWNER, J. G. Ekerdt, N. Arzate, B. S. Mendoza, V. Gavrilenko, and R. Wu, "Optical second
harmonic spectroscopy of boron-reconstructed Si(001)," Physical Review Letters 84, 3406-3409 (2000).
A
9
70 S. P. Le Blanc, E. W. Gaul and M. C. DOWNER, “Single-shot ultrafast phase measurement by frequency
domain holography,” Optics Letters 25, 764-766 (2000).
A
33
A
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Refereeed Journal Publications
updated 1/3/08
9
71 N. Andreev, M. V. Chegotov, M. C. DOWNER, E. W. Gaul, N. M. Matlis, A. A. Pogosova, and A. R. Rundquist,
"Propagation of intense laser pulses through inhomogeneous ionizing gas profiles," IEEE Transactions on
Plasma Science 28, 1090-1097 (2000).
C
8
72 D. Lim, M. C. DOWNER, J. G. Ekerdt, “Second-harmonic spectroscopy of bulk boron-doped Si(001),” Applied
Physics Letters 77, 181-183 (2000).
A
40
73 E. W. Gaul, S. P. LeBlanc, A. R. Rundquist, R. Zgadzaj, H. Langhoff and M. C. DOWNER, “Production and
characterization of a fully-ionized He plasma channel,” Applied Physics Letters 77, 4112 (2000).
A
18
74 Y. Jiang, P. T. Wilson, M. C. DOWNER, C. W. White and S. P. Withrow, “Second-harmonic generation from
silicon nanocrystals embedded in SiO2,” Applied Physics Letters 78, 766-768 (2001).
A
13
75 V. I. Gavrilenko, R. Q. Wu, M. C. DOWNER, J. G. Ekerdt, D. Lim, P. Parkinson, “Optical second harmonic
spectra of Si(001) with H and Ge ad-atoms: first principles theory and experiment,” Physical Review B 63,
165325-165332 (2001).
C
76 F. Breitling, R. S. Weigel, M. C. DOWNER, T. Tajima, “Laser pointing stability control by neural network in submicroradian regime,” Review of Scientific Instruments 72, 1339-1342 (2001).
D
29
77 M. C. DOWNER, B. S. Mendoza and V. I. Gavrilenko, “Optical second harmonic spectroscopy of
semiconductor surfaces: advances in microscopic understanding,” Surface and Interface Analysis 31, 966986 (2001).
A
2
78 M. C. DOWNER, Y. Jiang, D. Lim, L. Mantese, P. T. Wilson, B. S. Mendoza, and V. I. Gavrilenko, “Optical
second harmonic spectroscopy of silicon surfaces, interfaces and nanocrystals,” physica status solidi (a)
188, 1371-1381 (2001).
A
5
79 Y. Jiang, L. Sun, and M. C. Downer, “Second-harmonic spectroscopy of two-dimensional Si nanocrystal layers
embedded in SiO2 films,” Appl. Phys. Lett. 81, 3034-3036 (2002).
A
80 M. C. Downer, "A New Low for Nonlinear Optics," Science 298, 373-375 (2002).
A
6
81 P. T. Wilson, Y. Jiang, R. Carriles, and M. C. DOWNER, "Optical second-harmonic amplitude and phase
spectroscopy by use of broadbandwidth femtosecond pulses," J. Opt. Soc. Am. B 20, 2548-2561 (2003).
A
1
82 E. Mishina, N. Tanimura, S. Nakabayashi, O. A. Aksipetrov and M. C. DOWNER, "Photomodulated secondharmonic generation at silicon-silicon oxide interfaces: from modelling to application," Jpn. J. Appl. Phys. 42,
6731-6736 (2003).
C
83 K. Wu, J. D. Canterbury, P. T. Wilson and M. C. DOWNER, "Electric-field-induced second-harmonic
microscopy," phys. stat. sol. (c) 0, 3081-3085 (2003).
A
84 Jinhee Kwon and M. C. DOWNER, "Reflectance-difference and second-harmonic generation: a meeting of
two spectroscopies," phys. stat. sol. (c) 0, 3055-3060 (2003).
A
8
85 C. Chiu, M. Fomytskyi, F. Raischel, F. Grigsby, M. C. DOWNER and T. Tajima, "Laser accelerators for
radiation medicine: a feasibility study," Med. Phys. 31, 2042-2052 (2004).
C
10
86 K. K. Kainz, K. R. Hogstrom, J. A. Antolak, P. R. Almond, C. D. Bloch, C. Chiu, M. Fomytskyi, F. Raischel, M.
C. DOWNER and T. Tajima, "Dose properties of a laser accelerated electron beam and prospects for clinical
application," Med. Phys.31, 2053-2067 (2004).
C
2
87 R. Zgadzaj, E. W. Gaul, N. H. Matlis, M. C. DOWNER, and G. Shvets," Femtosecond pump-probe study of
preformed plasma channels," J. Opt. Soc. Am. B 21, 1559-1567 (2004).
A
2
88 M. Fomytskyi, C. Chiu, F. Grigsby and M. C. DOWNER, "Controlled plasma wave generation and particle
acceleration through seeding of the forward Raman instability," Physics of Plasmas 12, 023103 (2004).
A
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updated 1/3/08
12
89 P. Figliozzi, L. Sun, Y. Jiang, N. Matlis, B. Mattern, M. C. DOWNER, S. P. WIthrow, C. W. White, W. L.
Mochán and B. S. Mendoza, “Single-beam and enhanced two-beam second-harmonic generation from silicon
nanocrystals by use of spatially inhomogeneous femtosecond pulses,” Phys. Rev. Lett. 94, 047401 (2005).
A
3
90 L. Sun, P. Figliozzi, Y. Q. An, M. C. DOWNER, W. L. Mochán and B. S. Mendoza, “Nonresonant quadrupolar
second-harmonic generation in isotropic materials using two orthogonally polarized laser beams,” Optics
Letters 30, 2287-2289 (2005).
A
1
91 Jinhee Kwon, M. C. DOWNER and B. S. Mendoza, "Second-harmonic and reflectance-anisotropy
spectroscopy of vicinal Si(001)/SiO2 interfaces: experiment and simplified microscopic model," Phys. Rev. B
73, 195330 (2006).
A
1
92 R. Carriles, J. Kwon, J. C. Miller, Y. Q. An, M. C. DOWER, J. Price and A. C. Diebold, “Second-harmonic
characterization of Si/Hf1-xSixO2 interfaces,” Appl. Phys. Lett. 88, 161120 (2006).
A
1
93 R. Carriles, Y. Q. An and M. C. DOWNER, “Frequency-domain measurement of second harmonic phase,”
phys. stat. sol. (b) 242, 3001-3006 (2005).
A
94 J. Kwon and M. C. DOWNER, “Simplified bond model of spectroscopic SHG and RAS of oxidized and
reconstructed vicinal Si(001),” phys. stat. sol. (c) 2, 3973-3977 (2005).
A
95 L. Sun, P. Figliozzi, Y. Jiang, M. C. DOWNER, W. L. Mochán, B. S. Mendoza, “Second-harmonic
spectroscopy of nano-interfaces,” phys. stat. sol. (c) 2, 4067-4071 (2005).
A
96 D. Stoker, M.l C. DOWNER, M. F. Becker, J. W. Keto , “Optical third harmonic surface microscopy using
ultrashort laser pulses,” phys. stat. sol. (c) 2, 3978-3982 (2005).
D
97 B. T. Bowes, H. Langhoff, M. C. DOWNER, M. Wilcox, B. Hou, J. Nees and G. Mourou, “Femtosecond
microscopy of radial transport in a micron-scale Al plasma excited at relativistic intensity,” Optics Letters 31,
116-118 (2006).
A
98 J. A. Nees, B. Hou, N. M. Naumova, B. T. Bowes, A. Mordovanakis, E. Power, M. C. DOWNER, and G.
Mourou, ”Distinctive physical effects and applications approaching the relativistic labmda-cubed regime,” J.
Special Topics in Quantum Electronics 12, 223-232 (2006).
C
99 R. Carriles, J. Kwon, Y. Q. An, L. Sun, S. K. Stanley, J. G. Ekerdt, M. C. DOWNER, J. Price, T. Boescke, and
A. C. Diebold, “Optical characterization of process-dependent charging in hafnium oxide structures,” J. Vac.
Sci. Technol. B 24, 2160-2168 (2006).
A
7
100 N. H. Matlis, S. Reed, S. S. Bulanov, V. Chvykov, G. Kalintchenko, T. Matsuoka, P. Rousseau, V. Yanovsky, A.
Maksimchuk, S. Kalmykov, G. Shvets and M. C. DOWNER, “Snapshots of laser wakefields,” Nature Physics
2, 749-753 (2006).
A
2
101 B. Shim, G. Hays, R. Zgadzaj, T. Ditmire and M. C. DOWNER, “Enhanced harmonic generation from
expanding clusters,” Physical Review Letters 98, 123902 (2007).
A
102 T. Pfeifer and M. C. Downer, “Direct experimental observation of periodic intensity modulation along a
straight hollow core optical waveguide,” J. Opt. Soc. Am. B 24, 1025-1029 (2007).
A
103 K. Wu, R. Carriles and M. C. DOWNER, "Phase-sensitive electric-field-induced second-harmonic microscopy
of metal-semiconductor junctions," J. Opt. Soc. Am. B. 24, 2736-2740 (2007).
A
104 F. Grigsby, D. Peng and M. C. DOWNER, “Chirped-pulse Raman amplification for two-color high-intensity
laser experiments,” submitted to J. Opt. Soc. Am. B (2007).
A
105 Y. Q. An, R. Carriles and M. C. DOWNER, "Absolute phase and amplitude of second-order nonlinear optical
susceptibility components at Si(001) interfaces," Physical Review B 75, 241307(R) (2007).
A
106 Jinhee Kwon, R. Ehlert and M. C. DOWNER, "Optical second-harmonic and reflectance-anisotropy
spectroscopy of molecular adsorption on Si(001) step-edges," in preparation (2007).
A
2
page 7
Refereeed Journal Publications
updated 1/3/08
107 A. Maksimchuk, S. Reed, S. S. Bulanov, V. Chvykov, G. Kalintchenko, T. Matsuoka, N. H. Matlis, S. Kalmykov,
G. Shvets, M. C. DOWNER, C. R. Vane, J. R. Beene, D. Stracener, and D. R. Schultz, “Studies of laser
wakeifeld structures and electron acceleration in underdense plasmas,” Physics of Plasmas, in press (2008).
C
Book Chapters
53
*1 M. C. DOWNER, ‘The puzzle of two-photon rare earth spectra in solids.” in Laser Spectroscopy of Solids II,
ed. W.M. Yen (Springer-Verlag 1988), chapter 2, pp.29-75.
A
2
2
G. W. Burdick and M. C. DOWNER, "One-photon rare earth optical transitions: recent theoretical
developments." In Solid State Luminescence - Physics, Materials, and Devices, A. H. Kitai, ed., (Chapman
and Hall, 1992), chapter 1, pp 97-126.
A
2
3
M. C. DOWNER, H. Ahn, D. H. Reitze, D. M. Riffe, and X. Y. Wang, "Properties of condensed matter under
planetary interior conditions measured by femtosecond spectroscopy." In Laser Interactions with Atoms,
Solids and Plasmas, R. M. More, ed. (Plenum Publishing Corp., New York, 1994) pp. 249-271.
A
* cited both by book title "Laser Spectroscopy of Solids" (42) and series title "Topics in Applied Physics" (11)
3268
TOTAL CITATIONS (based on Science Citation Index via ISI Web of Science)