Photonics and Ultrafast Physics 1

The module contains the basics of modern optics, laser physics and focuses especially on the techniques and applications of ultrashort laser pulses. The following topics are addressed:

• Propagation of light rays in simple optical systems, ray transfer matrix analysis, scalar wave theory, Gaussian beam, optical resonators, stability, Fabry-Perot resonator
• Modern microscopy: Fourier optics, optical transfer functions, linear and nonlinear microscopy
• Nonlinear (NL) Optics: NL polarization, frequency conversion, parametric processes, collinear and non-collinear optical parametric oscillators (OPO) and amplifiers (OPA), self-phase modulation
• NL fiber optics: Fiber modes, nonlinear Schrödinger equation, solitons
• Laser technology: Fermis golden rule, atomics rate equations, laser energy levels, laser media, Q-switching and mode-locking

After successful completion of the module the students are able to

• describe and to predict the characteristics and the propagation of laser beams.
• apply matrix optics to simple linear optical systems and to understand optical resonators.
• apply fourier optics to problems concercning optical imaging and modern microscopy.
• understand methods of nonlinear optics and laser physics and apply them to problems concerning the generation, amplification and characterization of ultrashort laser pulses.
• understand and describe the propagation of ultrashort light pulses in optical fibers.
• know the basic principles of a laser, as well as the most important laser media.
• know the methods to generate short and intense light pulses.

No preconditions in addition to the requirements for the Master’s program in Physics.

In the thematically structured lecture, the theoretical basics are presented in form of an oral talk and the corresponding experimental techniques are outlined using descriptive examples. In the lecture and the according notes, examples for original publications are given, which serve to guide the students to deepen the contents learned as wells as to promote further literature work. A direct demonstration of the contents learned is offered in form of visits at the laboratories of the chair of laser and x-ray physics at the end of the lecture and an excursion to a large scale scientific facility.

Oral presentation, PowerPoint slides (especially figures), blackboard writing for the derivation of equations.

• B.E.A. Saleh & M.C. Teich: Fundamentals of Photonics, Wiley-Interscience, (2007)
• G.A. Reider: Photonik: Eine Einführung in die Grundlagen, Springer, (1997)

There will be an oral exam of 30 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using comprehension questions and sample calculations.

For example an assignment in the exam might be:

• What are the relations between wavelength, beam diameter and beam divergence of a Gaussian beam?
• Describe the optical transfer function of a simple system of lenses.
• Describe and explain the intensity and angle dependence of the second harmonic generation process.
• Explain the appearance of optical solitons using the nonlinear Schrödinger equation.
• Compare 2, 3 and 4-level laser media regarding the lasing process.