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CAS Lecture 2006 Illinois State University April 25, 2006 Enlightened by lasers Q. Charles Su Intense Laser Physics Theory Unit Illinois State University Support National Science Foundation US Department of Energy Research Corporation College of Arts & Sciences Department of Physics Light Newton, Edison (1879) lights up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach In the beginning there was no light … fire makes us happy A very brief history of light IN THE BEGINNING - (c 4.5 Billion BC) THE SUN - (c 4 Billion BC) THE EARTH - (c 4 Billion BC) EARLY LIFE - (c 3 Billion BC) PHOTOSYNTHESIS - (c 2 Billion BC) FIRST MAN - (c 1 Million BC) EARLY MAN - (c 500,000 BC) FIRE, FLAME and TORCH - (c 400,000 BC) PRIMITIVE LAMPS - (c 13,000 BC) ANIMAL LAMPS - (c 5000 BC) EARLY LIGHTING - (3000 BC) SUNDIAL - (c 1500 BC) OIL POTTERY LAMPS - GREEK - (600 BC) OIL RESERVOIR LAMP - (500 BC) ROMAN - LIFE & LIGHT - (400 BC - 80 AD) COLOR AND MUSIC (SOUND) - (c 350 BC) EARLY OPTICS & LENSES - (c 300 BC) HORN LANTERN - (c 100 AD) CANDLE - (c 400) CAMERA OBSCURA - (c 1000) COLORS OF THE SPECTRUM - (1666) POLARIZATION/POLARIZED LIGHT - (1678) PHOTOGRAPHY, EARLY - (1727) ADDITIVE COLOR MIXING - (1769) BETTY LAMP (& BETSY LAMP) - (1790) FIRST - GAS LIGHTING - (1792) INFRARED - (c 1800) ULTRAVIOLET LIGHT (UV) - (1801) ELECTRIC ARC LIGHT/ CARBON ARC LIGHT - (1809) PHOTOGRAPHY, MODERN - (1826) SPEED OF LIGHT - (1849) SPECTROSCOPE - (c 1850) KEROSENE LAMP - (1853) FIRST - FOLLOWSPOT SPOTLIGHT - (c 1856) PHOTOGRAPHY, MOTION PICTURES - EARLY - (1872) FIRST - ELECTRIC FILAMENT (INCANDESCENT) LAMP - (1874) EDISON LAMP - (1879) SWAN LAMP - (1879) FIRST - PHOTOCELL - (1880) ELECTRICITY - (1899) HIGH INTENSITY DISCHARGE (HID) LAMP - (1901) MERCURY-VAPOR LAMP - (1901) TUNGSTEN FILAMENT LAMP - (1907) GAS FILLED LAMP - (1913) FLASHBULB - (1930) SODIUM LAMP - (LOW PRESSURE) - (1932) FLUORESCENT LAMP - (1937) PHOTOGRAPHY - POLAROID CAMERA - (1947) FIBER OPTICS - (1955) LASER - (1960) HOLOGRAM/HOLOGRAPHY - (a 1960) QUARTZ HALOGEN LAMP - (1960) LIGHT EMITTING DIODE - (a 1965) wave theory Theories of light corpuscular theory Electromagnetic waves Christiaan Huygens 1629–1695 photons Sir Isaac Newton 1643 –1727 James Clerk Maxwell 1831–1879 Albert Einstein 1879–1955 Edison practically lit up the world laying of the mains and installation of the world's first permanent, commercial central power system in lower Manhattan, which became operative in September 1882. Light Newton, Edison lights (1879) up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach Laser usages precision CD player scanner printer power cutting, laser surgery temporal precision probe fast processes high temperature fusion photodynamic therapy cheaper / safer imaging photo density waves In the movies Laser shows Light Newton, Edison lights (1879) up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach Active medium (hurdles in a stadium) Hurdles ~ Atoms Hurdle in up position ~ population inversion Hurdle reset after fall down ~ external “pumping” A hurdle goes down, energy releases, a pigeon flies away pigeon ~ photon down randomly ~ spontaneous emission of light After many hurdles are down … No laser Now a pigeon with the right energy knocks down a hurdle… + = hurdle is down + 2 pigeons fly off exactly the same way ~ stimulated emission of light (Einstein) Start with one pigeon 2 64 2048 4 128 4096 8 256 8192 … (after 29 rounds) … (after 33 rounds) 16 512 16384 32 1024 32768 536,870,912 > US population 8,589,934,592 > world population all in concert with each other ~ light amplification Let pigeons turn around in the stadium and work hard… Then open up the stadium gate from time to time ~ Light Amplification by Stimulated Emission of Radiation Ingredients of a laser (1) Active medium with population inversion (2) Stimulated emission (3) Light amplification with resonator Light Newton, Edison lights (1879) up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach Laser laboratories and how they are related to my research Lab for Laser Energetics (U. Rochester) Laser fusion experiments Diagnostics temperature and density determinations x-ray imaging ISU-UR collaboration through the DOE NLUF grants Intense laser facilities around the world Saclay-France FOM-Holland MPQ-Germany SIOFM-China U Tokyo-Japan QOLS-UK ATT BrookHaven U Michigan ISU: Numerical/Gedanken experiments Ultra relativistic laser experiments planed DESY, Hamburg GSI-Darmstadt SLAC-Stanford CUOS-Ann Arbor ISU: Computer simulations, NSF grants Bio-optical imaging research Labs: U Penn, UC Irvine, U Mass, UI ISU: light scattering lab and MC computations Lund-Sweden URC-Canada LLL Modeling laser action on computers Physics and equations Computer programming Simulations of experiments ˆ ˆ b p (t)Wp (x) d n (t)Wn (x) ̂ (x,t) p n bˆ p (t) bˆ p' p U(t) p' dˆ n' p U(t) n' p' n' dˆ n (t) bˆ p' n U(t) p' dˆ n' n U(t) n' p' n' U(t)=T exp{–i∫0t dt’ [ca·p–a·A(x,t’)+bc2+V(x,t’)]} Result visualization Explanation More simulations Great space for (undergraduate) student involvement Fishing or cleaning fish ? Laboratory experiments guide theory Multiphoton ionization 1960s Above threshold ionization 1979– Higher order harmonic generation 1980s Computer experiments predict new physics? Atomic stabilization 1990 Cycloatom 2000 Klein paradox 2004 Bioimaging 2005 Laser Laser-atom interaction – A microscopic view Outcome 1: bound + QuickTi me™ and a TIFF ( Uncompressed) decompr essor are needed to see thi s p icture. atom + Outcome 2: ionized – + – How does ionization vary with laser intensity ? Computer simulation of atomic ionization V(x) 1/ 1 x2 Model atom (Rochester model) J. Javanainen, J.H. Eberly and Q. Su Phys. Rev. A 38, 3430 (1988) Interaction with laser Solve: Schrödinger equation Pick a laser intensity I Current QM state future state Compute ionization for each state Gedanken experiment on computer: Ionization beyond 1016 W/cm2 ionization all ionized 100% IN weak 0 ? strong super strong laser intensity 10 –6 P(t) 10 –4 P(t) I2 P(t) I3 P(t) I4 I N T E N S I T Y Ionization Suppression! I4 I > 1016 W/cm2 P(t) I5 P(t) I6 10 0 Ionization P(T) I1 L A S E R P(T, I) P(t) 10 -1 4 5 1st 6 recovery7 2nd 3rd 3 2 1 -2 0 10Laser 10 10I2 intensity, I (a.u.) P(t) I7 Su, Eberly, Javanainen PRL, 64, 862, ’90 Laser intensity Electron spatial density stabilization Outcome 3: stabilized ionization Outcome 2: ionized atom 0 Outcome 1: bound space Su, Laser Phys. 3, 241 (1993) Gavrila, Atoms in Intense Fields (1992) + – – + + – Computer prediction: Stabilization Normally + – Increased intensity increases ionization more chance for electron to pick up energy around nucleus At super-strong fields Laser also distorts electron orbits reduces the chance of interaction with nucleus + Other theoretical studies and experimental evidence Kulander et al, Atoms in Intense Laser Fields Ed Gavrila, (1992) Keitel and Knight, Phys. Rev. A 51,1420 (1995) van Druten, et al Phys. Rev. A 55 622(1997) Longhi, et al, Phys. Rev. Lett. 94, 073002 (2005) – Stabilization and recoveries of ionization 10 0 P(T, I) 1st recovery 10 -1 10 -2 10 0 I (a.u.) 2nd 3rd 10 2 S nl=S Su, Irving*, Johnson*, Eberly, J. Phys. B 29, 5755 (1996) Su, Irving*, Eberly, Laser Phys. 7, 568 (1997) Users of the Rochester model atom Quick Time™a nd a TIFF ( Unco mpre ssed ) dec ompr esso r ar e nee ded to see this pictur e. > 128 groups in 23 countries Light Newton, Edison lights (1879) up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach Dream: to build an imaging device … safer than x-ray CT cheaper than MRI better resolved than ultrasound Possible solution: IR laser based imaging Imaging schemes shadow-gram (like x-ray, CAT) x-ray shadow reflection-gram (like ultra-sound) ultrasound scatter-gram (infrared lasers) laser Forward problems (predict the future) medium —> scattered light Inverse problems (predict the past) medium <— scattered light Light-medium interaction computer simulations FFT on the grid method QuickTime™ and a Video decompressor are needed to see this picture. Pane of glass Wanare, Su and Grobe, PRE 62, 8705 (2000) QuickTime™ and a Video decompressor are needed to see this picture. Random medium X-rays vs laser light QuickTime™ and a GIF decompressor are needed to see this picture. Monte Carlo Simulation S. L. Jacques and L.-H. Wang, in Optical Thermal Response of Laser Irradiated Tissue, edited by A. J. Welch and M. J. C. van Gemert (Plenum Press, New York, 1995), pp. 73-100. Complication of laser-based image reconstruction • X-ray • Laser Modulation of light induces beam narrowing =0 0 wide beam narrow beam Transverse light beam waist Qui ckTime™ and a TIFF (U ncompr essed) decompressor are needed to see thi s pi cture. Intensity I() () () Distance from optical axis Pulse width () shrinks with increasing frequency ISU filed patent application in 2005 Beyond theory: experiment? Output Fiber z Input Laser Laboratory measurements for on axis light intensity S. Campbell, A. O’Connell, S. Menon, Q. Su and R. Grobe, PRE, submitted experiment Log(N) 8 simulation theory I theory II 8 z=0cm 6 4 z=10cm 4 0 z=5cm 2 -0.6 0 10 20 -0.4 -0.2 0 y [cm] 30 0.2 0.4 z [cm] 0.6 40 Light Newton, Edison lights (1879) up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach Matter creation from light? E = mc2 Light = electron + positron Laser intensity > 1026 Mourou, Yanovsky Opt. Ph. News 15, 40 (2004) Popular science articles on matter creation from light “Conjuring matter from light” Science, Aug, 29, 1997 “Real photons create matter” Physics News, Sept. 18, 1997 “Light work” New Scientist, Sept. 27, 1997 “Boom! From light comes matter” Photonics Spectra, Nov. 1997 “Matter from light” CERN Courier, Nov. 1997 “E=mc2, really” Scientific American, Dec. 1997 “Let there be matter” Discover, Dec. 1997 “Gamma rays create matter by plowing into laser light” Phys. Today, Feb 1998 Wave or particle description of matter ? Traditional wave view Dirac Equation (1928) deals with physics after creation (no creation) Particle view Quantum Field Theory (1940s) deals with # of creation (no wave nature) ????????????? Computational QFT Phys. Rev. Lett. (2004) wave nature during creation (new framework) What are these nice graphs? Solution of the field operator for e– and e+ ˆ (x,t) ˆ (x,t)= [ c a·p–a·A+bc2+V ] Dirac equation for field it Solution ˆ (t)W (x) dˆ (t)W (x) where ˆ b (x,t) p p n n p bˆ p (t) bˆ p' p U(t) p' dˆ n' p U(t) n' p' n dˆ n (t) bˆ p' n U(t) p' dˆ n' n U(t) n' n' p' n' U(t)=T exp{–i∫0t dt’ [ca·p–a·A(x,t’)+bc2+V(x,t’)]} Krekora, Su, Grobe, PRL 92, 040406 (2004) ; PRL 93, 043004 (2004) Braun, Su, Grobe, PRA 59, 604 (1999) C.H. Keitel, Cont. Phys. 42, 353 (2001) A.D. Bandrauk, H. Shen J. Phys. A, 7147 (1994) From quantum field theory to quantum mechanics F(x,y,t) = <0|| vacuum state ˆ (+)(x,t) positive frequency part ˆ c(+)(y,t) || F(t=0)> charge conjugation initial state S.S. Schweber, “An introduction to relativistic quantum field theory” The space-time resolved pair creation energy e– e+ Sample projects that employed the new CQFT method (1) Space time resolved pair creation (2) Klein paradox, 70 years old Phys. Rev. Lett. 92, 040406 (2004) Phys. Rev. A 72, 064103 (2005) (3) Localization and Zitterbewegung Phys. Rev. Lett. 93, 043004 (2004) (4) Entanglement J. Mod. Opt. 52, 489 (2005) (5) Modified Schwinger formula Las. Phys. 15, 282 (2005) (6) Supercritical bound states Phys. Rev. Lett. 95, 070403 (2005) (7) Interpretational difficulty in QED Phys. Rev. A, 73, 022114 (2006) Experimental verification? Time dependent colliding ions (existing) Static supercritical field Experimental plans: CUOS Ann Arbor, Michigan DESY Hamburg, Germany GSI SLAC Darmstadt, Germany Stanford, California Laser fields lead to new unions of Particle Gravitational Atomic Plasma Astro-physics Cosmology Enlightened ? QuickT ime ™an d a TIFF ( Uncomp res sed) deco mpre ssor ar e need ed to see this pictur e. Light Newton, Edison lights (1879) up Manhattan (1882) Laser usages CD writer, player, laser pointer, scanner, light knife, cosmetic treatment, laser show What’s in a laser active medium, stimulated emission, resonator Maiman, Townes, MIT echo off moon Probing matter with lasers Ionization process, world map Medical imaging, patent Matter creation, Klein Research vs education ILP approach Graduate or Undergraduate US, best graduate school system in the world > 50% Nobel in Science after WWII good research-industry relation What about our pre-graduate education Cuts in education funding Flat science funding Math/Science not “cool” in school Do we need to change the perception? Undergraduate physics research at ISU Large number of students Large number faculty mentors National awards Show cased at conferences Center or Research and Education on Nanostructures Center for Research and Instruction in Space Physics Intense Laser Physics Theory Unit Surface Science Lab Polarized Electron Lab Atomic Structure Statistical Mechanics Nonlinear Dynamics Mathematical Physics QuickTi me™ and a TIFF (U ncompressed) decompressor are needed to see this picture. Undergraduate research at ILP Our approach Start early Small group collaboration Project design, execution, completion Know physics, math, programming Use intuition, catch misconception Communicate result with others Thanks to funding agencies Big thanks to colleagues past and present Support from CAS, RSP, Honors Program Physics faculty colleagues Postdoctoral fellows All 35 undergraduate students Especially Prof. Grobe for collaborations QuickTime™ and a Photo - JPEG decompressor are needed to see this picture. QuickTi me™ and a TIFF ( Uncompressed) decompressor are needed to see thi s pi ctur e. QuickTi me™ and a TIFF ( Uncompressed) decompr essor are needed to see thi s picture. Thanks to Alex, Christina, and Jean! QuickT ime ™an d a TIFF ( Uncomp res sed) deco mpre ssor ar e need ed to see this pictur e. Thanks for attending Quic kT i me™ and a T IFF (Unc ompres s ed) dec ompres s or are needed t o s ee thi s pi c ture. and enjoy some refreshment !