Laser Physics

Course Description

Theory of light-matter interaction. Quantum model of atom. Lorentz model of absorption and emission. Homogenous and inhomogeneous line broadening. Einstein coefficient A and B. Basic elements of lasers. Three and four-level laser scheme. Gain saturation. Cavity modes. Stable and unstable laser resonators. Longitudinal and transversal laser oscillation. Puls lasers (Q swiching, mode coupling). Lasers with gaseous medium: (He-Ne, Ar+, N2, CO2 laser, excimer lasers (ArF, KrF), chemical lasers.. Solid state lasers (ruby, Nd: YAG, fiber lasers). Semiconductor lasers (GaAs). Dye lasers. Free-electron lasers. Application of lasers in physics, technique and medicine with emphasis on two-step optical recording and system of optical signal recognition.

General Competencies

The goals of this course are: to provide students with the fundamentals of laser physics, and enable them to successfully apply lasers in their respective disciplines; to give students an understanding how to successfully achieve results combining knowledge gained from different disciplines (in the course students see how the elements from electro-magnetism, quantum physics, semiconductor theory and electronics are brought together and applied to the field of lasers); help students to develop critical thinking skills; to prepare students for careers in high-tech industries.

Learning Outcomes

  1. Describe the interaction of light with matter using classical and semi-classical theories.
  2. Explain the operation of laser rezonator and laser theshold.
  3. Explain the special properties of laser radiation compared to more conventional sources.
  4. Explain the meaning of Q-switching and mode-locking in puls lasers.
  5. Understan how the choice and characteristics of laser materials and rezonator determine the ultimate behavior of a laser.
  6. Analyising the properties of laser determine possible applications.
  7. Evaluate the multi-disciplinary nature of engineering systems.

Forms of Teaching

Lectures

The examples are solved during the lectures.

Laboratory Work

Laboratory experiments are on Department of applied physics. Laboratory is mandatory. Laboratory: 1. Index of refraction (deviation of laser beam on prism). 2. Absorption coefficient of solution (laser power measurements). 3. Measurement of diameter of laser beam. 4. Faraday effect.

Consultations

Consultations are held in arrangement with the professor.

Seminars

Seminar is mandatory.

Internship visits

Visit the company Dok-ing and Institut of physics. (if possible)

Grading Method

Continuous Assessment Exam
Type Threshold Percent of Grade Comment: Percent of Grade
Laboratory Exercises 0 % 16 % 0 % 16 %
Class participation 0 % 5 % 0 % 5 %
Seminar/Project 0 % 15 % 0 % 15 %
Mid Term Exam: Written 0 % 32 % 0 %
Final Exam: Written 0 % 32 %
Exam: Written 0 % 32 %
Exam: Oral 32 %

Week by Week Schedule

  1. Characteristics of light radiation: wave-particle duality of light. Introduction: basic elements of lasers. Laser cooling of atoms.
  2. Quantum model of atom. Quantum numbers. Selection rules. Light emission and absorption. Examples.
  3. Widths and profiles of spectral lines. Lorentz model of absorption and emission. Doppler line broadening. Examples. Expriment: atomic and molecular spectra.
  4. Collisional line broadening.Termal radiation and Plancks law. Einstein probability of spontaneous, stimulated emission and absorption. Examples.
  5. Population inversion in three and four-level laser. Electro-magnetic waves in cavity. Spectral mode density. Fabri-Perot interferometer. Examples.
  6. Treshold condition. Gain saturation. Modes of laser resonators: Gauss, Hermite-Gauss, Laguerre-Gauss and Bessels modes. Examples.
  7. Multilayer dielectric coatings. Laser resonators: stable and unstable. Quality factor of laser resonator.
  8. Midterm exam.
  9. Excitation of laser medium. Optical pumping. Electron excitation. Second-order collisions. Sngle-mode lasers. Spectral resolving power of prism, optical grating and Fabry-Perot etalon. Examples.
  10. Multimode lasers. Puls lasers (Q switching, mode coupling). Spectral characteristic of laser radiation: monochromaticity, directionality, spectral brightness, coherence time and length. Puls kasers. Maser. Lasers with gaseous medium: He-Ne, Ar+ ion.
  11. N2 laser. Molecular spectra. CO2 laser.
  12. Excimer lasers: ArF, KrF. Chemical lasers. Dye lasers. Solid-state lasers (ruby, Nd: YAG, fiber). Tunable solid-state lasers.
  13. Semiconductor lasers (GaAs). X-ray lasers. Free-electron lasers. Fiber lasers, Detectors of laser radiation.
  14. Holography. Recording and reconstruction of hologram. Matematcal description. Hologram types. Hologram recording materials. Applications: interferometry, optical data processing, holographic memories.
  15. Final exam.

Study Programmes

University graduate
Computer Engineering (profile)
Mathematics and Science (2. semester)
Computer Science (profile)
Mathematics and Science (2. semester)
Control Engineering and Automation (profile)
Mathematics and Science (2. semester)
Electrical Engineering Systems and Technologies (profile)
Mathematics and Science (2. semester)
Electrical Power Engineering (profile)
Mathematics and Science (2. semester)
Electronic and Computer Engineering (profile)
Mathematics and Science (2. semester)
Electronics (profile)
Mathematics and Science (2. semester)
Information Processing (profile)
Mathematics and Science (2. semester)
Software Engineering and Information Systems (profile)
Mathematics and Science (2. semester)
Telecommunication and Informatics (profile)
Mathematics and Science (2. semester)
Wireless Technologies (profile)
Mathematics and Science (2. semester)

Literature

V. Henč-Bartolić, L. Bistričić (2001.), Predavanja i auditorne vježbe iz fizike lasera, Element
W. Demtröder (2008.), Laser spectroscopy, Springer
O. Svelto (1998.), Principles of lasers, Plenum Press
P.W. Milonni, J.H. Eberly (1988.), Lasers, John Willey & Sons
S. Lugomer (1990.), Laser Techology: Laser-Driven Processes, Prentice Hall

Grading System

ID 86467
  Summer semester
4 ECTS
L1 English Level
L1 e-Learning
45 Lecturers
0 Exercises
4 Laboratory exercises

General

85 Excellent
75 Very Good
60 Good
50 Acceptable