PHYS 599B: Optics, Spectroscopy, PHYS 599B: Optics, Spectroscopy, Ultrafast Laser PhenomenaUltrafast Laser Phenomena

Who: beginning researchers in science and engineering with introductory quantum mechanics and solid state physics/chemistry who are interested in lasers, ultrafast laser science and technology, nonlinear optics, nanoscale science and correlated electron systems

Course philosophy: key concepts/models, techniques and understandingsstart from scratch & Introduce concepts as they appeargain insights into diverse spectroscopy techniques and data analysis methodsmaster a non-sequential way of learning fill understanding gaps in some research sub-fields difficulty: classical semi-classical fully quantized

http://www.cmpgroup.ameslab.gov/ultrafast/PHYS590B

J. Wang

Course formatCourse formatLectures, short seminars & discussionsLectures, short seminars & discussions

1:10 3:00 every Tuesday

Lecture (50 minutes) by J. Wang

Break (10 minutes)

Presentation #1 (25 minutes) (10 minutes) + discussion (10-15 minutes)

Presentation #2 (25 minutes) (10 minutes) + discussion (10-15 minutes)

Things we will be talking aboutThings we will be talking aboutLight sources and tools, science/technology enabledLight sources and tools, science/technology enabled

1st week General discussion on this course, timescales, order of magnitude, atoms, photons and solids, lasers

2nd week Overview: linear and nonlinear optics, ultrafast science and technology, time-resolved spectroscopy

3rd week Basic optics and light-matter interaction (I): optical susceptibilities, refraction and absorption, dipole oscillator model of a solid

4th week Basic optics and light-matter interaction (II): atomic polarizabalities, two-level atoms interacting with semi-classical field

5th week Basic laser physics: rate equation model of the laser, gain saturation, lasering, transverse and longitudinal modes, stability zone

6th week Ultrafast and nonlinear optics: ultrashort laser pulses, dispersion, 2nd and 3rd order nonlinearities

7th week Ultrafast lasers: ultrashort pulse generation, ultrafast amplifier, ultrabroadband generation, attosecond

Things we will be talking aboutThings we will be talking aboutLight sources and tools, science/technology enabledLight sources and tools, science/technology enabled

8th week: Static optical spectroscopy: FTIR, Raman/Rayleighscattering, multi-photon spectroscopy/microscopy

9th week: Time-resolved optical spectroscopy basic concepts and instrumentations

10th week: Coherent transient spectroscopy11th week: Ultrafast differential transmission/reflection spectroscopy:

from visible, near-IR to mid-IR and THz12th week: Magneto-optics and ultrafast magneto-optical spectroscopy13th week: Selected topics: ultrafast photo-emission, transient grating

spectroscopy, time-resolved photoluminescence, ultrafast electron diffraction, ultrafast X-ray spectroscopy

14th week: Selected topics: optics of semiconductor nanostructures, quantum wells, wires and dots, single-wall carbonnanotubes, nano-particles, coherent control in femto-chemisitry, magnetic semiconductors, correlated electrons and more complex systemsFinal presentation and wrap up

ScoreScore

Problem sets (occasionally) 10% Classroom discussion 10% Final presentation/reports 80%

1. Conduct a through literature search on an assigned topic

2. Describe what is new and why is interesting

3. Describe who did what and identify the seminar paper

4. Describe what is understood and what is not

5. Describe what is controversial

6. Try to propose a smoking gun experiment

Problems, discussions & finalsProblems, discussions & finals

No required! No required! course materials will be drawn from reviewcourse materials will be drawn from review articles, articles, summer school lectures and recent book chapterssummer school lectures and recent book chapters

Some Recommended General References:

Lasers/Optical Spectroscopy:

Demtroder, Laser Spectroscopy: Basic Concepts and Instrumentation

A. Sigman, Lasers

Max Born and Emil Wolf, Principles of optics

Ultrafast Science and Technology, nonlinear optics

Diels and Rudolph (DR), Ultrashort Laser Pulse Phenomena

Rulliere, Femtosecond laser pulses

Boyd, Nonlinear optics

Applications of ultrafast spectroscopy to solid state physics/chemistry

J. Shah, Ultrashort Spectroscopy of Semiconductors and Semiconductor Nanostructures

Chemla, D.S., Ultrafast Transient Nonlinear Optical Processes in Semiconductors

Mukamel, S, Principles of Nonlinear Optical Spectroscopy

Text booksText books

TimescaleTimescales in Nature s in Nature

Its routine to generate pulses < 1 picosecond (10-12 s).

Researchers generate pulses a few femtoseconds (10-15 s) long.

Such a pulse is to one minute as one minute is to the age of the universe.Such a pulse is to one second as 5 cents is to the US national debt.

1 minute

10 fs light pulse Age of universe

Time (seconds)

Computer clock cycle

Camera flash

Age of pyramids

One month

Human existence

10-15 10-12 10-9 10-6 10-3 100 103 106 109 1012 1015 1018

1 femtosecond 1 picosecond

How fast is ultrafast? How fast is ultrafast?

Order of magnitudeOrder of magnitudein atoms, photons and solids in atoms, photons and solids

Atom fields:H-atom ao = 0.53, Ry = 13.6 eV

2ao Eat = Ry Eat 2.6*109 V/cm

Light fields:I(W/cm2) E(V/cm) nph(cm-3)

Mercury Lamp 1 10 108

CW Laser 10 30 109

Pulsed Laser 109 104 1017

Focused pulsed Laser 1015 106 1023

Order of magnitudeOrder of magnitude

Solids:

1023 particles/cm3, quasi-particles and elementary excitationsVF 107 cm/s = 1 /fs Tlo = 2/lo = 115fsTpl = 2/pl = 150fs for neh = 5*1017cm-3

Semiconductors Doping neh =1019 1020 cm-3, m=0.07 mo, =12, ao = 140,

Ry = 4.2 meV

Device Physicse.g., semiconductor Laser: P=1W, Wo 1m, I = 104W/cm2

atoms, photons and solids atoms, photons and solids

Light is, in short, the most Light is, in short, the most refined form of matter.refined form of matter.

Louis de Broglie

Optics Optics a brief historya brief history

17th-century 18th-century 19th-century 20th-century

Kepler,Huygens

.

Total internal reflection, Telescope, geometrical optics, the wave theory, prism dispersion, the particle theory of light

Newton Fresnel, Young

Interference, diffraction,expressions for reflected and transmitted waves,unified electricity and magnetism

MaxwellMichelson

Einstein

Light is (1) a phenomenon of empty space(2) both a wave and a particle

Most fundamental questions, many prestigious names Most fundamental questions, many prestigious names

The story beginsThe story beginsAlbert Einstein, 1917Albert Einstein, 1917

First proposed a theory to elucidate the physical process behind laser

called stimulated emission

but it will take your guys long time to prove it!

First demonstration: Maiman, 1960

The Amazing LightThe Amazing Light LaserLaser

A laser will lase if the beam increases in irradiance during a round trip:that is, if I3 > I0.

Light amplification of stimulated emission of radiation

The worldThe worlds largest lasers largest laserAlmost 10 years journey, just dedicated!

192 shaped pulses; 1.8 MJ total energy

National Ignition Facility(LLNL)

Nova

~ 250 10-18 s13 nm

What is the shortest event ever created?What is the shortest event ever created?A single attosecond pulse