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Enlightened by lasers Q. Charles Su Intense Laser Physics Theory Unit Illinois State University PowerPoint Presentation
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  1. Enlightened by lasersQ. Charles Su Intense Laser Physics Theory UnitIllinois State University CAS Lecture 2006 Illinois State University April 25, 2006 Support National Science Foundation US Department of Energy Research Corporation College of Arts & Sciences Department of Physics www.phy.ilstu.edu/ILP

  2. 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

  3. In the beginning there was no light …

  4. fire makes us happy

  5. 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)

  6. 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

  7. 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.

  8. 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

  9. 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

  10. In the movies

  11. Laser shows

  12. 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

  13. Active medium (hurdles in a stadium) Hurdles ~ Atoms Hurdle in up position ~ population inversion Hurdle reset after fall down ~ external “pumping”

  14. A hurdle goes down, energy releases, a pigeon flies away pigeon ~ photon down randomly ~ spontaneous emission of light

  15. After many hurdles are down … No laser

  16. 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)

  17. Start with one pigeon  2  4  8  16  32  64  128  256  512  1024  2048  4096  8192  16384  32768  … (after 29 rounds)  536,870,912 > US population … (after 33 rounds)  8,589,934,592 > world population all in concert with each other ~ light amplification

  18. 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

  19. Active medium with population inversion (2) Stimulated emission (3) Light amplification with resonator Ingredients of a laser

  20. 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

  21. 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 Lund-Sweden SIOFM-China U Tokyo-Japan QOLS-UK URC-Canada ATT BrookHaven U Michigan LLL 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

  22. Modeling laser action on computers (x,t) = U(t)=T exp{–i∫0t dt’ [ca·p–a·A(x,t’)+bc2+V(x,t’)]} Simulations of experiments Computer programming Physics and equations Result visualization Explanation More simulations Great space for (undergraduate) student involvement

  23. 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

  24. Laser atom + + + – – – Laser-atom interaction A microscopic view Outcome 1: bound Outcome 2: ionized How does ionization vary with laser intensity ?

  25. Computer simulation of atomic ionization Model atom (Rochester model) J. Javanainen, J.H. Eberly and Q. Su Phys. Rev. A 38, 3430 (1988) Solve: Schrödinger equation Pick a laser intensity I Interaction with laser Current QM state  future state  Compute ionization for each state

  26. Gedanken experiment on computer: Ionization beyond 1016 W/cm2 ionization all ionized ? 100% strong IN super strong weak laser intensity 0

  27. P(t) Ionization Suppression! P(t) L A S E R I N T E N S I T Y I4 I1 I > 1016 W/cm2 P(t) P(t) I2 I5 P(t) P(t) I6 I3 5 4 P(t) 6 P(t) 7 Ionization P(T) 3 I7 I4 2 1 Laser intensity, I Su, Eberly, Javanainen PRL, 64, 862, ’90

  28. stabilization Outcome 3: stabilized Laser intensity ionization Outcome 2: ionized + + – – atom Outcome 1: bound + – space 0 Electron spatial density Su, Laser Phys. 3, 241 (1993) Gavrila, Atoms in Intense Fields (1992)

  29. + – + – 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)

  30. Stabilization and recoveries of ionization S n l = S Su, Irving*, Johnson*, Eberly, J. Phys. B 29, 5755 (1996) Su, Irving*, Eberly, Laser Phys. 7, 568 (1997)

  31. Users of the Rochester model atom > 128 groups in 23 countries

  32. 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

  33. Dream: to build an imaging device … safer than x-ray CT cheaper than MRI better resolved than ultrasound Possible solution: IR laser based imaging

  34. Imaging schemes shadow shadow-gram (like x-ray, CAT) x-ray reflection-gram (like ultra-sound) ultra- sound scatter-gram (infrared lasers) laser

  35. Forward problems (predict the future) medium —> scattered light Inverse problems (predict the past) medium <— scattered light

  36. Light-medium interaction computer simulations FFT on the grid method Wanare, Su and Grobe, PRE 62, 8705 (2000) Pane of glass Random medium

  37. X-rays vs laser light 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.

  38. Complication of laser-based image reconstruction • X-ray • Laser

  39. Modulation of light induces beam narrowing  = 0 0 wide beam narrow beam

  40. Intensity I     Distance from optical axis  Transverse light beam waist    Pulse width  shrinks with increasing frequency  ISU filed patent application in 2005

  41. Beyond theory: experiment? Input Laser Output Fiber z

  42. Laboratory measurements for on axis light intensity S. Campbell, A. O’Connell, S. Menon, Q. Su and R. Grobe, PRE, submitted

  43. 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

  44. Laser intensity > 1026 Matter creation from light? E = mc2 Light = electron + positron • Mourou, Yanovsky • Opt. Ph. News 15, 40 (2004)

  45. 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

  46. 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) ?????????????

  47. Many body quantum field theory What are these nice graphs?

  48. Solution of the field operator for e– and e+ it (x,t)= [ c a·p–a·A+bc2+V ] (x,t) Dirac equation for field where Solution (x,t) = 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|| (+)(x,t) c(+)(y,t) || F(t=0)> positive frequency part initial state charge conjugation vacuum state S.S. Schweber, “An introduction to relativistic quantum field theory” Of course! Now everything makes sense!

  49. The space-time resolved pair creation energy e– e+

  50. 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)