1. Optics and Photonics Selim Jochim together with Dr. K. Simeonidis
MPI für Kernphysik und
Uni Heidelberg
Website for this lecture:  teaching

2. What will you learn in this course?
How to use advanced photonics instruments and technology in the laboratory
Learn to develop your own ideas on how to make use of photonics for (precision) experiments
Knowlegde that is widely needed in many labs in Heidelberg:
Biomedical research
Laser spectroscopy
High-power “ultrafast” lasers for atomic physics
Laser cooling and trapping, (quantum) manipulation of atoms, molecules or ions

3. Motivation
We make (increasingly) heavy use of photonics in our daily life. Two interesting examples:
Green laser pointers emit bright light at 532 nm: How are they made?  make use of almost anything you will learn in this course!!
DVD reader/writer ( resolution of a microscope for a few €!!)

4. Contents Preliminary list:
11.4. Geometric optics, rays (Fermat’s principle)
18.4. No class
25.4. Wave optics, gaussian beams (paraxial Helmholtz eq.)
2.5. Polarization optics, optical coatings, wave guides, …
9.5. Atom-photon interaction
16.5. Lasers: Light amplification
23.5. Laser oscillation, optical resonators

5. Contents II 30.5. More lasers, solid state lasers, dye lasers, etc.
6.6. Pulsed lasers: Q-switching, mode locking, extremely short pulses
13.6. Semiconductor photonics: detectors, LEDs, Lasers
20.6. Fourier optics, holography
27.6. Nonlinear optics concepts
4.7. Nonlinear optics applications: Frequency doubling, mixing ..
11.7. Advanced applications: Frequency comb, optical synthesizer ...
18.7. Lab tour(s)

6. Recommended literature
Saleh, Teich: Fundamentals of Photonics
Kneubühl, Sigrist: Laser
Davis: Lasers and Electro-Optics: Fundamentals and Engineering
Demtröder: Laserspektroskopie
Hecht, Optics (Especially for the first few lectures)

7. 1. Geometric (ray) optics
Light propagates as rays with “speed of light”, c in vacuum
In a medium, the light is slowed down by the refractive index n
In an inhomogeneous system, propagation is governed by Fermat’s principle:
“Minimize” optical path length:

8. Fermat’s principle Phenomenologically:
Hero of Alexandria (ca. 70 – 10 A.D.): Light always takes the shortest path when reflected from a surface:

9. Refraction A
Zeichung B

10. Interfaces between dielectrics …
n2>n1 …
Total internal reflection ….
critical angle:

11. Where total internal reflection is used
Prisms, e.g. binoculars, camera viewfinder
Optical fibers:

12. Parabolic mirror Parallel beams are focused onto a single spot:
Car headlight!

13. Spherical mirror, paraxial rays
Paraxial rays: Assume that all beams propagate “close” to optical axis.
In most cases, this means that sin q≈ tan q ≈ q
Rays are focused to
F=R/2

14. Imaging with spherical mirrors

15. Thin lenses

16. Paraxial imaging
Magnification

17. Matrix formalism for parax. rays
Use it to describe a complex optical system with a single (2,2)-matrix
Define state of a ray by a 2-comp. vector:
valid if

18. Example matrices
Free space propagation
Refraction at a surface

19. Optical system ….

20. When the paraxial approx. fails …
Focussing of a laser beam:
Plano-convex lens,
also “best form lens”
Minimize non-paraxial distortions:

21. Spherical aberration …
Can we make all parallel rays incident on a lens end up in a single spot??

22. Aspheric lens?
Optical path length should be the same for all angles ….

23. Aspheric lenses All kinds of quality grades available
All kinds of quality grades available
Molded, plastic material

24. Precision machined … ASPHERIC LIMITS STANDARD HIGH PRECISION
STANDARD
HIGH PRECISION
Diameter (mm)
15-120
Length (mm)
Width (mm)
Dimensional Tolerances (µm) 25 5
Center Thickness Tolerance (µm)
100 35
Wedge Tolerance (µm) 75
Surface Quality
60-40
10-5
Radius Limits (mm)
LRC Limited
Concave
>30.0
Convex
>5.0
Radius Tolerance (%)
0.1
0.05
Total SAG (mm)
<25
Aspheric Surface Accuracy (wave)  
1/4
1/10