Autumn Semester 2020 takes place in a mixed form of online and classroom teaching.
Please read the published information on the individual courses carefully.

Steven Johnson: Catalogue data in Autumn Semester 2016

Name Prof. Dr. Steven Johnson
Institut für Quantenelektronik
ETH Zürich, HPT D 15
Auguste-Piccard-Hof 1
8093 Zürich
Telephone+41 44 633 76 31
Fax+41 44 633 10 54
RelationshipFull Professor

402-0101-00LThe Zurich Physics Colloquium Information 0 credits1KR. Renner, G. Aeppli, C. Anastasiou, N. Beisert, G. Blatter, S. Cantalupo, M. Carollo, C. Degen, G. Dissertori, K. Ensslin, T. Esslinger, J. Faist, M. Gaberdiel, T. K. Gehrmann, G. M. Graf, R. Grange, J. Home, S. Huber, A. Imamoglu, P. Jetzer, S. Johnson, U. Keller, K. S. Kirch, S. Lilly, L. M. Mayer, J. Mesot, B. Moore, D. Pescia, A. Refregier, A. Rubbia, K. Schawinski, T. C. Schulthess, M. Sigrist, M. Troyer, A. Vaterlaus, R. Wallny, A. Wallraff, W. Wegscheider, A. Zheludev, O. Zilberberg
AbstractResearch colloquium
Prerequisites / NoticeOccasionally, talks may be delivered in German.
402-0402-00LUltrafast Laser Physics Information 10 credits3V + 2UL. P. Gallmann, S. Johnson, U. Keller
AbstractIntroduction to ultrafast laser physics with an outlook into cutting edge research topics such as attosecond science and coherent ultrafast sources from THz to X-rays.
ObjectiveUnderstanding of basic physics and technology for pursuing research in ultrafast laser science. How are ultrashort laser pulses generated, how do they interact with matter, how can we measure these shortest man-made events and how can we use them to time-resolve ultrafast processes in nature? Fundamental concepts and techniques will be linked to a selection of hot topics in current research and applications.
ContentThe lecture covers the following topics:

a) Linear pulse propagation: mathematical description of pulses and their propagation in linear optical systems, effect of dispersion on ultrashort pulses, concepts of pulse carrier and envelope, time-bandwidth product

b) Dispersion compensation: technologies for controlling dispersion, pulse shaping, measurement of dispersion

c) Nonlinear pulse propagation: intensity-dependent refractive index (Kerr effect), self-phase modulation, nonlinear pulse compression, self-focusing, filamentation, nonlinear Schrödinger equation, solitons, non-instantaneous nonlinear effects (Raman/Brillouin), self-steepening, saturable gain and absorption

d) Second-order nonlinearities with ultrashort pulses: phase-matching with short pulses and real beams, quasi-phase matching, second-harmonic and sum-frequency generation, parametric amplification and generation

e) Relaxation oscillations: dynamical behavior of rate equations after perturbation

f) Q-switching: active Q-switching and its theory based on rate equations, active Q-switching technologies, passive Q-switching and theory

g) Active modelocking: introduction to modelocking, frequency comb versus axial modes, theory for various regimes of laser operation, Haus master equation formalism

h) Passive modelocking: slow, fast and ideally fast saturable absorbers, semiconductor saturable absorber mirror (SESAM), designs of and materials for SESAMs, modelocking with slow absorber and dynamic gain saturation, modelocking with ideally fast saturable absorber, Kerr-lens modelocking, soliton modelocking, Q-switching instabilities in modelocked lasers, inverse saturable absorption

i) Pulse duration measurements: rf cables and electronics, fast photodiodes, linear system theory for microwave test systems, intensity and interferometric autocorrelations and their limitations, frequency-resolved optical gating, spectral phase interferometry for direct electric-field reconstruction and more

j) Noise: microwave spectrum analyzer as laser diagnostics, amplitude noise and timing jitter of ultrafast lasers, lock-in detection

k) Ultrafast measurements: pump-probe scheme, transient absorption/differential transmission spectroscopy, four-wave mixing, optical gating and more

l) Frequency combs and carrier-envelope offset phase: measurement and stabilization of carrier-envelope offset phase (CEP), time and frequency domain applications of CEP-stabilized sources

m) High-harmonic generation and attosecond science: non-perturbative nonlinear optics / strong-field phenomena, high-harmonic generation (HHG), phase-matching in HHG, attosecond pulse generation, attosecond technology: detectors and diagnostics, attosecond metrology (streaking, RABBITT, transient absorption, attoclock), example experiments

n) Ultrafast THz science: generation and detection, physics in THz domain, weak-field and strong-field applications

o) Brief introduction to other hot topics: relativistic and ultra-high intensity ultrafast science, ultrafast electron sources, free-electron lasers, etc.
Lecture notesClass notes will be made available.
Prerequisites / NoticePrerequisites: Basic knowledge of quantum electronics (e. g., 402-0275-00L Quantenelektronik).
402-0415-62LModern Topics in Terahertz Science Information 6 credits2V + 1US. Johnson
AbstractThis course reviews current research topics in Terahertz Science with a strong focus on scientific applications in physics, chemistry and biology, as well as the emerging field of nonlinear THz optics.
ObjectiveTerahertz frequency electromagnetic radiation lies at the border between electronics and optics, and as such has many unique properties that make it well-suited to study the electronic, magnetic and structural properties of many materials. The course objective is to give students the ability to identify problems of current interest in physics, chemistry, materials science and biology that can be potentially addressed using terahertz photonics and to design potential experimental solutions.

The course will focus predominantly on understanding research conducted over the last 4-5 years at the forefront of this developing field, with a strong emphasis on nonlinear THz science which has only recently become possible. This in particular has generated excitement as it offers potential new ways to control chemical reactions and/or phase transitons in materials.
ContentTopics to be discussed in the class include:

1) Overview of THz & interactions with matter
2) THz generation and detection
3) Linear THz spectroscopies
4) Imaging
5) Nonlinear THz interactions
Lecture notesScripts will be distributed via moodle.
LiteratureThe readings for the course will draw mostly on current journal articles that will be distributed in class/via moodle. There is also a general textbook listed below available electronically via the ETH library system. You can also order a black-and-white paperback via an "on-demand" system for a pretty reasonable price.

Principles of Terahertz Science and Technology, Yun-Shick Lee (Springer, 2008).
Prerequisites / NoticePrerequqisites: Quantum electronics.

The former course title of this course is "Terahertz Technology and Applications".