4 ECTS credits
120 h study time

Offer 1 with catalog number 4020324ENR for all students in the 1st semester at a (E) Master - advanced level.

1st semester
Enrollment based on exam contract
Grading method
Grading (scale from 0 to 20)
Can retake in second session
Taught in
Partnership Agreement
Under interuniversity agreement for degree program
Faculty of Engineering
Applied Physics and Photonics
Educational team
Guy Verschaffelt
Nathalie Vermeulen (course titular)
Geert Morthier
Activities and contact hours
36 contact hours Lecture
12 contact hours Seminar, Exercises or Practicals
Course Content


  • Basic laser physics: Introduction; Absorption; Spontaneous and stimulated emission of light; Amplification; Basic laser setup; Gain, saturation and line broadening
  • Basic properties of laser light: One direction; One frequency; One phase; Laser light is intense


  • Introduction: The need for more than two energy levels; Rate equations for a 4-level laser
  • Continuous-wave (cw) laser action: Output power in cw regime; Influence of experimental parameters; Transients              
  • Pulsed laser action: Introduction; Gain switching; Q-switching; Cavity dumping; Mode-locking; Ultra-short pulses


  • Introduction
  • Modes in a confocal resonator: Wave fronts; Frequencies; Transverse light distribution
  • Modes in a non-confocal resonator: Stability criteria; Frequencies
  • Modes in a waveguide resonator: Modes in a fiber waveguide resonator; Modes in an on-chip waveguide resonator
  • Modes in a (free-space/waveguide) ring resonator
  • Modes in a real laser: Line broadening; Selection of modes
  • Saturation and hole-burning effects: Spatial hole burning; Spectral hole burning


  • Gaussian beams: Basic Formulas; Propagation; Transformation by a lens and focusing; Transmission through a circular aperture
  • Multimode beams: Introduction; Spot radius W for a multimode beam; Beam Propagation Factor M; A more theoretical approach; Practical use


  • General introduction
  • Gas lasers: General; Neutral gas (He-Ne); Ionized gas (argon ion); Molecules (CO2); Excimer lasers (ArF)
  • Liquid lasers (dye laser)
  • Solid-state lasers: General; Rare-earth-doped lasers (Nd:YAG and Er:fiber); Transition-metal-doped lasers (Ti: Sapphire); Changing the wavelength by optical nonlinear effects
  • Other lasing mechanisms: Raman lasing


  • Geometry and important characteristics
  • Material aspects: heterostructures, gain and absorption, low dimensional materials,
  • Gain saturation
  • Fabry-Perot laser diodes: cavity resonance
  • Fabry-Perot laser diodes: rate equations and dynamic operation
  • Noise: power spectrum and phase noise, injection locking


  • Distributed Feedback and Distributed Bragg Reflector laser diodes
  • Vertical Cavity Surface Emitting Laser diodes
  • Tunable laser diodes
  • Quantum cascade lasers
  • Laser diode packaging

This course is part of the European Master of Science in Photonics. Chapters 1 to 5 are taught by N. Vermeulen, both at VUB and UGent. Chapters 6-7 are taught by G. Verschaffelt at VUB and by G. Morthier at UGent.

Course material
Digital course material (Required) : Lasers, Syllabus, Nathalie Vermeulen, Guy Verschaffelt, Geert Morthier
Handbook (Recommended) : Principles of Lasers, O. Svelto, 5th edition, Plenum Press, New York, 9781489977137, 2016
Additional info

This course is part of the European Master of Science in Photonics.

The course material consists of the following:

- Lecture notes (syllabus) + slides (English)

- Exercise sheets are provided during the lectures


Optional handbook: O. Svelto, Principles of Lasers (5th edition), Plenum Press, New York, 2010.



Learning Outcomes

Algemene competenties


Since their invention in 1960, lasers have become the most important light sources in optics and photonics, and are present everywhere in modern society nowadays. For example, worldwide telecommunication is based on the transmission of laser signals through optical fibers, and today’s manufacturing industry heavily relies on the use of high-irradiance laser beams. Other application domains include medicine, art restoration, remote sensing, biological spectroscopy, and many others. It is the general aim of this course that the students will become able to explain and analyse laser properties and laser-related concepts, that they learn to construct and analyse the mathematical description of important concepts, and that they are also able to apply the latter to practical examples on the use of lasers.


The targeted end competences can be categorized as follows:

  • The students are able to name, describe and explain laser properties and concepts, including:

spontaneous and stimulated emission, absorption, coherence, heterostructures for efficient light generation, light propagation in a resonator, continuous-wave and pulsed laser action, line broadening, saturation, Gaussian laser beams, operation and applications of different laser types (gas lasers, liquid lasers, solid-state lasers, semiconductor lasers), laser dynamics, noise, Bragg gratings, wavelength tuning, laser packaging.

  • The students have the ability to derive from first principles the mathematical description for laser-related concepts, including:

rate equations describing the general operation principle of laser action and formulas for continuous-wave/pulsed laser operation, formulas for the modes in different types of resonators with different stability criteria, equations for propagation and transformation of Gaussian and multimode laser beams in optical systems, laser rate equations for different types of semiconductor lasers, formulas describing the gain and complex refractive index in semiconductor materials, description of the linewidth of lasers, formulas for the dynamic behaviour of lasers.

  • The students know how to explain and analyse the above-enlisted mathematical descriptions for laser-related concepts.
  • The students are able to apply the mathematical descriptions to practical examples and to use these descriptions to solve practical problems.


The students are evaluated according to the above-enlisted end competences in an oral exam with written preparation (open questions, closed book)




The final grade is composed based on the following categories:
Other Exam determines 100% of the final mark.

Within the Other Exam category, the following assignments need to be completed:

  • exam oral + written with a relative weight of 1 which comprises 100% of the final mark.

    Note: Oral exam with written preparation, open questions, closed book

Additional info regarding evaluation

Oral exam with written preparation (open questions, closed book)

The part of the course taught by N. Vermeulen and the part of the course taught by G. Verschaffelt (at VUB) or G. Morthier (at UGent) are examined together.

Partial transfer of the score obtained for an individual part to the 2nd session or the next academic year is not allowed.

Allowed unsatisfactory mark
The supplementary Teaching and Examination Regulations of your faculty stipulate whether an allowed unsatisfactory mark for this programme unit is permitted.

Academic context

This offer is part of the following study plans:
Master of Photonics Engineering: On campus traject
Master of Photonics Engineering: Online/Digital traject
Master of Electrical Engineering: Standaard traject BRUFACE J