Physics of Light
Physics of Light
Regular modules
These modules are offered for „Physics of Light“ on a regular basis. Please note: Each module usually corresponds to a single course with the same title. In a few cases, a module is linked to two courses which will then have different titles.
Summer term
Prof. Dr. Joly, Prof. Dr. Chekhova, 5 ECTS
 Linear properties of materials.
 Origin of the nonlinear susceptibility.
 Importance of phasematching.
 Second harmonic generation, derivation of the set of coupled equations.
 Importance of the initial phase and case of seeding second harmonic generation. Use of birefringence to achieve phasematching.
 Electrooptic effects.
 Nonlinear process in relation to third order nonlinearity.
 Modulation instability, soliton formation, perturbations of soliton, and supercontinuum generation.
 Application: nonlinear optics in photonic crystal fibers.
Prof. Dr. Chekhova, 5 ECTS
 Basic concepts of statistical optics
 Spatial and temporal coherence. Coherent modes, photon number per mode
 Intensity fluctuations and Hanbury Brown and Twiss experiment
 Interaction between atom and light (semiclassical description)
 Quantization of the electromagnetic field
 Quantum operators and quantum states
 Heisenberg and Schrödinger pictures
 Polarization in quantum optics
 Nonlinear optical effects for producing nonclassical light
 Parametric downconversion and fourwave mixing, biphotons, squeezed light
 Singlephoton states and singlephoton emitters
 Entanglement and Bell’s inequality violation
Prof. Dr. Joly, 5 ECTS
This module naturally follows the “Basics of Lasers” module and aims at deepen the knowledge on a few specific aspects of lasers. In particular we will study the Zcavity of one of the most popular laser system: the Titanium: sapphire laser. The purpose here is to show why simpler cavity is not possible. It requires understanding properly the concept of stability of laser cavity and introduces the problem of astigmatism. In a second stage we see how dispersion effects can hamper the properties of a modelocked laser system and see how to circumvent this. We then study the different method used to characterize ultrashort laser pulse. This starts from basics concepts of autocorrelation but review more advanced techniques allowing to retrieve fully the amplitude and phase of a laser pulse. Towards the end of the lecture several topics are possible and it will be chosen together with the students. This can be for instance (i) the polarization and the Jones’ formalism (ii) the MaxwellBloch equations (iii) the origin of spontaneous emission. Finally in order to broaden the contents of the lecture the students are asked to prepare one halfanhour presentation of the topics of their choice. The topics are discussed during the first two sessions of the lecture and must focus on a physical aspect of laser.
Prof. Dr. Hartmann, 5 ECTS
 Introduction and Historical Overview
 Recap of Quantum Mechanics
States, wavefunctions and operators; time evolution and superpositions; measurements; qubits; composite quantum systems; the exponential Hilbert space; density matrices; dissipation  Quantum Computing Basics
Models of quantum computation; gate model; adiabatic quantum computing  Quantum Algorithms for Fault Tolerant Quantum Computers
Deutsch’s problem; classical circuits; quantum circuits; gates; some applications of the CNOT gate; universal sets of gates; Can a quantum computer do classical computations efficiently? How hard is it to simulate a quantum computer with a classical computer? Simon’s problem; quantum Fourier transform; phase estimation; Shore’s factoring algorithm; solving systems of linear equations  Quantum Error Correction
repetition code; stabilizer formalism; surface codes; toric code; planar surface codes  NISQ Quantum Computing
Today’s quantum hardware; variational algorithms; Quantum Approximate Optimization Algorithm (QAOA); quantum simulation
Prof. Dr. C. Marquardt, Prof. Dr. Schmauß, 5 ECTS
 Introduction to quantum communication: Motivation and practical impact
 Introduction and refresh of fundamentals of quantum mechanics
 Basics of information theory
 Definition of a quantum state in quantum optics
 Fundamental principle of quantum key distribution
 Fundamental principle of quantum communication
(classical and quantum capacity)  Detailed steps of quantum key distribution
 Security proofs (epsilon security)
 Modulation of quantum states
 Detection of quantum states
 Electronics for coherent communication
 Error correction codes
 Practical implementations
 Combination with classical cryptography
 Fiberbased systems
 Free space and satellitebased systems
 Quantum repeaters
 Lab course „Physics of Light“
Winter term
Prof. Dr. von Zanthier, 10 ECTS
The module discusses lightmatter interaction in different systems as well as the quantum nature of light. Emphasis is put onto the laser. Starting from the theory of optical resonators and Gaussian beams we review the generation of laser light on a microscopic level (MaxwellBloch equations) and examine its principal characteristics. Various applications of laser light in quantum optics, laser spectroscopy, laser cooling and trapping of atoms and in nonlinear optics are investigated. In addition we review various quantum optical phenomena like photon statistics, photon bunching/antibunching, multiphoton interferences, intensity interferometers and resonance fluorescence.
Prof. Dr. Götzinger, Prof. Dr. Joly, 5 ECTS
 Photonic Crystal Optics
 Laser/ Pulsed light / pulse propagation
 Guided wave optics
 Fiber optics
 Photonic crystal fibers
 Optical resonators / microresonators
 Acousto optics/spatial light modulator
 Metamaterials
 Orbital angular momentum
 Superresolution
Prof. Dr. Joly, Dr. Fattahi, Prof. Dr. Chekhova, 5 ECTS
 Nonlinear propagation in solidcore photonic crystal fibres (modulation instability, fourwave mixing, soliton dynamics, supercontinuum generation) and in hollowcore photonic crystal fibres (generation of tunable dispersive waves, plasma in fibres)
 Nonlinear optical effects (parametric downconversion, fourwave mixing, modulation instability) for the generation of nonclassical light (entangled photons, squeezed light, twin beams, heralded single photons).
 Nonlinear effects for generating high energy sub cycle pulses (kerrlens modelocking, Yb:YAG laser technology, optical parametric amplification, pulses synthesis, attosecond pulse generation)
 Lab course „Physics of Light“
Further modules
Theses modules were given irregularly during the previous semesters and might be offered again, but there is no guarantee.
Prof. Dr. C. Marquadt, 5 ECTS
In this module we will introduce and discuss fundamental concepts of quantum communication and talk about recent developments. Topics include: Introduction to quantum information concepts, quantum optics: preparation and measurement of quantum states, concepts of quantum cryptography and the BB84 protocol, quantum key distribution with discrete variables: modern protocols, QKD with continuous variables, modern quantum key distribution security proofs, quantum repeaters, quantum communication with satellites, quantum random number generation
After the module students
 comprehend an interesting physical topic in a short time frame
 identify and interpret the appropriate literature
 select and organize the relevant information for the presentation
 compose a presentation on the topic at the appropriate level for the audience
 use the appropriate presentation techniques and tools
 criticize and defend the topic in a scientific discussion
Prof. Dr. Chekhova, 5 ECTS
 Twophoton absorption with entangled photons
 Fibre sources of nonclassical light
 Nanoscale quantum nonlinear optics
 Sensing ‘with undetected photons’
 Nonlinear optics with noble gases
 The ’simplest‘ nonlinear optical system: a single atom
 Quantum optics with parabolic mirrors
 Machine Learning for Quantum State Estimation
 Artificial Intelligence for Designing Quantum Optics Experiments and Photonic Devices
Prof. Dr. F. Marquardt, 5 ECTS
This module aims at covering a few special topics in the interactions between quantum matter (atoms, molecules) and quantum light. The first part of the course will present fundamental aspects such as light field quantization, spontaneous emission, stimulated emission and absorption, cavity quantum electrodynamics. The second part of the course makes use of the introduced concepts to allow the understanding of laser theory, laser cooling, cavity cooling and cavity optomechanics. The mathematical tools involved are quantum master equations and quantum Langevin equations.
Prof. Dr. Chekhova, 5 ECTS
 Polarization of light: definition, brief history, role in photonics
 Jones vector and Jones matrices
 Stokes parameters and Müller matrices
 Poincare sphere representation: states, transformations
 Optical elements that we use in the lab
 Geometrical phase
 Crystal optics: birefringence, Fresnel surfaces, uniaxial and biaxial crystals, walkoff
 Polarization in nonlinear optics: phase and group matching
 Polarization in quantum optics: operators0 Polarization in quantum optics: states
 Quantum key distribution with polarized photons.
Prof. Dr. Hartmann, 5 ECTS
The course provides an introduction to quantum computing. The development of quantum hardware has progressed substantially in recent years and has now reached a level of maturity where first industrial applications are being explored. This course will introduce the fundamental ingredients of quantum algorithms, quantum bits and quantum gates, the most important hardware implementations and in particular algorithms that can run on near term hardware implementations of so called Noisy Intermediate Scale Quantum (NISQ) devices. The course will be completed with introductions to the basic concepts of error correction, which is needed in the next stage of development to fully exploit the potential of this emerging computing technology. Prerequisites: the main concepts of quantum theory, including quantum states, the Schrödinger equation, unitary evolution and measurements.
Dr. Roland Gillen, 5 ECTS
The lecture series will discuss modern (and less modern) theoretical methods for the simulation of optical spectra of crystalline materials. A focus will lie on the proper description of excitonic and trionic contributions, which are important in one and twodimensional materials. Examples in the form of calculations and paper reviews will be integrated into the lectures.
Selected topics are:

Excitons in solid, particularly one and twodimensional materials

Effective massbased approaches

Tightbinding

Modern ab initio methods, such as densitymatrix based approaches and the excitonic BetheSalpeter Equation
Reading material containing the contents of the lecture and recordings from a previous lecture series will be available on StudOn.
Prof. Dr. Schmidt, 5 ECTS
The nobel prize is the most prestigious award in physics. Here we focus on nobel prizes for the quantum theory of light and matter. This field is an important cornerstone of modern physics and the largest research pillar of our physics department. Goal of this seminar is to gain an understanding and overview of the most prominet topics in this field.
Prof. Dr. Schmidt, 5 ECTS
Students
 comprehend an interesting physical topic in a short time frame
 identify and interpret the appropriate literature
 select and organize the relevant information for the presentation
 compose a presentation on the topic at the appropriate level for the audience
 give a presentation to a scientific audience and use the appropriate presentation techniques and tools
 criticize and defend the topic in a scientific discussion