by
Dr. A. Volkmer

Course
objectives

Lasers
today: Scientific and technical applications

Specific
properties of laser light (an overview)

Historical
review

Twolevel
system (Einstein coefficients, Lorentzian line shape function and lifetime)

Blackbody
radiation (spectral mode density and energy density (Plancks
formula), limiting cases and consequences for Laser operation)

The
Laser principle (amplification by stimulated emission, amplified stimulated
emission (ASE, without cavity), light amplification by stimulated emission
radiation (Laser, with cavity), rate equation analysis, 3 and 4level laser)

The
phase space cell (longitudinal and transversal uncertainty of a wave packet)

Complex
representation of light waves

The
superposition principle (1^{st} order coherence function, complex
degree of coherence and visibility, The WienerKintchine
theorem)

Coherence
of damped waves (the wave packet)

Photon
statistics (2^{nd} order coherence function, BoseEinstein distribution
for thermal light, Poissonian distribution for
coherent laser light, subPoissonian distribution for
nonclassical light)

Example:
Coherence of photons from a single quantum system

Ray
matrix derivation of resonator stability criterion (paraxial ray transfer matrix
approximation, ray position for periodic system, stability diagram for
spherical mirror resonator)

Wave
optics description of Gaussian beams (solution of the paraxial Helmholtz
equation (TEM modes))

Description
of Gaussian beams (confocal parameter, beam waist)

Axial
(longitudinal) modes (resonance frequencies for Gaussian modes, mode degeneracy
in a confocal symmetric resonator)

Interferometer
(twobeam interferometer (Michelson, MachZehnder, Sagnac), the FabryPerot
interferometer)

Passive
optical resonator (reflection and diffraction losses)

Active
optical resonator (Laser)

Transversal
and longitudinal mode selection

Mode
stability (Laser intensity and frequency stabilization schemes)

Generation
of ultrashort laser pulses (Qswitching, active and passive modelocking)

Wavepacket
description of modelocked laser pulses (group velocity dispersion, selfphase
modulation)

Pulse
compression techniques

Experimental
characterization of ultrashort laser pulses (2^{nd} order autocorrelation
techniques, frequencyresolved optical gating (FROG))

Nonlinear
polarization (the nonlinear wave equation)

Symmetry
properties of the nonlinear susceptibility tensor

Classical
anharmonic oscillator model

Phasematching
requirements

Chi(2)
processes (secondharmonic and sumfrequency generation (SHG and SFG), differencefrequency
generation (DFG), optical parametric amplification and oscillation (OPA and
OPO), optical rectification (OR), the Pockels effect)

Chi
(3) processes(thirdharmonic generation (THG), optical Kerreffect
(selffocusing, selfphase modulation), stimulated Raman scattering (SRS), coherent
antiStokes Raman scattering (CARS))

Highharmonic
generation of coherent radiation

Gas
lasers; different excitation mechanisms (atomic gas laser (He/Ne), metal vapor
laser (Cu, Pb, Au), ionic gas laser (Ar+, Kr+, Xe+, Cd+), molecular
gas lasers: infrared CO2 laser; the CO laser; farinfrared (FIR) lasers: CH3Br,
CH3F, H2O/D2O, HCN, excimer and exciplex superradiators / lasers, the nitrogen (N2) superradiator/laser)

Liquid
dye (solution) lasers (continuous and pulsed operation; tunability;
ultrashort pulse generation)

Solid
state lasers (undoped crystal lasers (excitonic lasers), doped crystal and glass lasers (dopant
is laseractive): Ruby (Cr3+/Al2O3); Alexandrite (Cr3+/BeAl2O4); Emerald
(Cr3+/BeAl2Si6O18); Titaniumsapphire (Ti3+/Al2O3); NeodymiumYAG (Y3Al5O12); Ndglass; ChromiumLiSAF
(LiSrAlF6); Er3+: YAlO3 upconversion laser)

Semiconductor
lasers (injection laser diode, distributedfeedback laser diode (DFB), vertical
cavity surface emitting laser diode (VCSEL), quantum well laser)

Other
(exotic) Lasers (chemical lasers (HF, I laser), the FreeElectronLaser
(FEL), Xray lasers (Se24+; tabletop lasers))