During the Fall semester: August – December, 2024.
This course is taught during the Fall semester at the Department of Electrical and Computer Engineering of Aarhus University. It is part of the Photonics teaching portfolio.
The objective of the course is to acquaint the student with the main photonic devices, their integration onto a photonic integrated circuit and the applications of this technology. This will be achieved by first introducing some fundamentals of light-matter interaction. Then an overview of the most important photonic devices will be presented. It will be discussed how these photonic devices can be considered as building blocks that can be combined into a circuit and which material systems can be used for that. Emphasis will be put on the required trade-offs and the main differences between material systems.
After this course the student should be familiar with the main photonic devices and the main platforms for photonic integration that are available. The student should be able to make a design study, with a qualitative understanding of the required trade-offs and a quantitative knowledge of the typical component and/or circuit operation parameters.
The participants must at the end of the course be able to:
ECTS credits: 10
Course coordinator: Nicolas Volet
Compulsory programme: Active participation.
Prerequisites: Electromagnetism, Optics.
Course assessment:
Oral examination based on written report. Design project with written report.
Seven-point grading scale. Internal co-examination.
This course addresses the core photonic engineering technologies such as diode lasers, optical fibers, and photonic integrated circuits, and their applications in communications, sensing and metrology. It is of interest to engineers who want to become active in the field of photonics, as well as to electrical engineers who want broaden their scope and anticipate on the exponentially increasing convergence of electronics and photonics.
The course will first introduce the fundamentals of light-matter interaction in semiconductors, focusing on effects like optical gain and absorption, light emission and optical waveguiding. The main electro-optic components, such as LEDs, laser diodes, modulators and detectors will be discussed. Finally it will be shown how these components can be combined into a photonic integrated circuit, also known as an optical chip. The main integration platforms, for example silicon nanophotonics and indium phosphide photonics, and their fabrication technology will be discussed. Applications of photonic devices and circuits in communications, microwave technology, and biomedical sensing and imaging will be reviewed.
The content of the course is summarized into several booklets. These booklets are meant to be concise and include all mathematical steps.
1. Light-matter interaction (Aug. 26 + 29)
Introduction/overview.
Bandgap and semiconductors.
Generation of light. Spontaneous/stimulated emission.
2. PN junction (Sept. 2 + 5)
Recap on modes
PN junction
3. Material platforms (Sept. 9 + 12)
Confinement of current + confinement of light
Materials for photonics
4. (Sept. 16 + 19)
Materials for photonics
*to update*––> Sept. 22 (Friday): deadline to submit group abstracts
5. Recombination processes (Sept. 23 + 26)
Growth. Lattice matching. Dislocations and quantum dots.
Dangling bonds and passivation.
Band structure.
Wafer fusion and heterogeneous integration.
Radiative recombination. Auger process. Phonons.
*to update*Sept. 25 (Monday): feedback on abstracts
6. (Sept. 30 + Oct. 3)
Infrared C-band:
scattering, attenuation and dispersion
Mid-infrared lasers:
quantum cascade lasers (QCLs) or difference-frequency generation (DFG)
HiTran database.
Deep-UV photonics:
Lasers, fibers and detectors
Nonlinear crystals and lithography
*to update*🍕––> Oct. 5 (Thursday) at 12:00:
Pizzas and guest lecture from Peter Tønning, Senior System Engineer at UV Medico
7. Optical amplification (Oct 7 + 10)
Erbium-doped fiber amplifiers (EDFAs).
Wavelength division multiplexing (WDM).
*to update*––> Oct. 12 (Thursday): group presentations
*to update*Oct. 13 (Friday): R-Day starting at 13:00 at 5122-122
The R-day event is an open forum for engagement and discussions among researchers and students within ECE. It aims at creating awareness and promoting research activities.
8. Semiconductor optical amplifiers (Oct. 21 + 24)
Transverse confinement factor. Net gain and saturation.
Semiconductor optical amplifiers (SOAs). Small-signal gain factor.
9. Laser performance (Oct. 28 + 31)
Condition for lasing threshold. Gain clamping.
Rate equations for the carrier and the photon densities.
Output power versus current.
10. Dynamics (Nov. 4 + 7)
Turn-on delay.
Small-signal modulation.
Wavelength chirp.
*to update*––> Nov. 8 (Wednesday): deadline to submit individual abstracts
*to update*Thursday (Nov. 9): Feedback on abstracts + exam preparation
11. Reflectors (Nov. 11 + 14)
Thin films and anti-reflective (AR) coatings.
Distributed Bragg reflectors (DBRs).
Corrugated waveguides.
Fiber Bragg gratings (FBGs).
Fabry-Perot interferometer and etalon.
Wavelength stabilization.
12. Narrow-linewidth lasers (Nov. 18 + 21)
Intrinsic linewidth and coherence length.
Fiber lasers.
Optical feedback.
External-cavity diode lasers (ECDLs).
*to update*––> Nov. 20 (Monday) at 10:15:
Guest lecture from Asger Sellerup Jensen, Senior Market Development Manager & Head of Quantum at NKT Photonics
Video: MPG
13. Pulses and incoherence (Nov. 25 + 28)
Speckle effect.
SLEDs: superluminescent light-emitting diodes.
Optical gyroscopes.
Isolators and circulators.
Stabilization loop: Pound-Drever-Hall (PDH) method.
*to update*––> Nov. 30 (Thursday): deadline to submit intermediate individual reports
14. Phase modulation (Dec. 2 + 5)
Modulators. Side-band generation.
*to update*––> Dec. 7 (Thursday): individual presentations (rehearsal)
*to update*––> Dec. 17 (Sunday): deadline to submit final individual reports
Extra topics
Modulation formats. Coherent communications.
Q-switching.
SESAMs: Semiconductor saturable absorber mirror.
Photodetectors.
Solar cells to ultrafast coherent receivers.
Mid-infrared detectors to solar-blind UV sensors.
Brillouin effect and distributed optical sensing.
Raman spectroscopy.
For numerical simulations of modes in waveguides, we will use the software EMode Photonix.
Information on how to get started can be found here.
A design study, summarized in a 5-page report.
For those that would like to attend the exam, please send your abstract and report to Nicolas Volet by email before the above deadlines.
The exam is oral, and the duration is 20 min.
We ask you to prepare a presentation for 10 min, leaving 10 min for questions.
At the exam, there will be a co-examiner internal to AU.
A design study, summarized in a 5-page report.
For those that would like to attend the exam, please send your report to Nicolas Volet by email before the above deadline.
The exam is oral, and the duration is 20 min.
We ask you to prepare a presentation for 10 min, leaving 10 min for questions.
At the exam, there will be a co-examiner internal to AU.
The 7-point grading scale is used for the assessment.
Below are applications notes on recent hot topics in photonics. They are meant to provide a brief entry point for a broad audience.
Other useful links are provided below.
RP Photonics Encyclopedia
An encyclopedia of optics and optoelectronics, laser technology, optical fibers, nonlinear optics, optical communications, imaging science, optical metrology, spectroscopy and ultrashort pulse physics.
Thorlabs
An American privately held optical equipment company. In addition to their products, Thorlabs' website contains technical resources that include tutorials, application notes, white papers, lab facts, etc.
European Photonics Industry Consortium (EPIC)
A not-for-profit association that serves the photonics community through a regular series of workshops, market studies and partnering.
EPIC also manages the website Jobs in Photonics.
Optica
The largest collection of peer-reviewed optics and photonics content.
LaTeX files (for booklets and exercises) are available at this Overleaf project.
Slides and other files are available at this SharePoint site.
