Lasers: theory and modern applications

Although the basic principles of lasers have remained unchanged in the past 50 years, there has been a significant shift in the kinds of lasers generating interest. Providing a comprehensive introduction to the operating principles and applications of lasers, this course reveals the latest developments and applications of lasers, as well as the manipulation, propagation and methods of detection of coherent radiation. Placing more emphasis on fundamental optical physics and applications of lasers, the course is structured in a series of self-contained modules suitable to physicists, chemists, engineers or biologist with advanced interests in lasers and detection.

The examination will be based on a written exam (80% of the grade) and 2 quizzes (week 6 and week 13) (20% of the grade)

Content of the 1st Lecture

• History of the Maser and Laser
• Electromagnetic waves, Maxwell equations 
• The Lorentz model of refractive index  

Reading: Scriptum (Polycopy) Chapter 1,2,3 

References (contained in the Polycopy):

• Milonni “Laser”, Chapter 3.1, 3.3 and 3.4   [Lorentz Model]
• Milonni “Laser”, Chapter 2.1  page 21,22 and 2.3  [Maxwell equation and wave vector]
• Milonni “Laser Physics”, Chapter 3.4 [Absorption]

• Physics Today [Reflection the first Laser]
• OPN article [Reflections on the first Maser]
• How many principles does it take to change a light bulb…into a laser?  [Invited Comment on Physica Scripta]
  

Content of the 2nd Lecture: Electron oscillator (Lorentz) model

• Quantum mechanical modification in the Lorentz model
• Spontaneous emission and optical gain
• Doppler broadening

Literature References (contained in chapter 3 in polycopy):

• The absorption coefficient and Lineshape function [Milonni, “Lasers”, Chapter 3.6 or “Laser Physics” Chapter 3.4]
• Bohr atomic Model [Milonni, “Laser”, Chapter 4.1-4.4]
• The Doppler broadening [Milonni, “Laser”, Chapter 3.11 or “Laser Physics”, Chapter 3.9 ]
• 
  

Supplementary information (Not a requirement, only for the interested reader):

• Matter wave interference in C60, Nature, Zeilinger
• On the Quantum mechanical model for atom-field interaction, Milonni, “Lasers” , Chapter 6
• Oscillator model and Quantum Mechanics, Milonni, “Laser Physics”, Appendix 3.16 and following

Content of the 3rd Lecture: laser systems I: 3 and 4 level lasers, gas lasers 

• Atom and photon rate equations, gain saturation
  
• 3 and 4 level lasers systems, threshold lasing condition

Litterature reference:

• • Chapter 5 Scriptum: laser resonator and laser threshold
  • Chapter 6 Scriptum: laser system examples (3-4 levels, rate equ.)
    

Supplementary information (Not a requirement, only for the interested reader):

• Single layer atomic mirror , Nature 2018
• random laser, Nature 2008

Content of the 4th Lecture: laser systems II

• cont. 3 and 4 level lasers systems, threshold lasing condition
  
•  gas lasers :He-Ne, Ar-Ion, CO2, Excimer
• solid state lasers: Nd-YAG, Disk Laser, semi-conductor

Litterature reference:

• Chapter 6 Scriptum: laser system examples (3-4 levels, rate equ.)

Supplementary information (Not a requirement, only for the interested reader):

• 400 Watts, cw green laser

Content of the 5th lecture: how fast can a laser be modulated, amplitude and phase noise, Allan Variance, Wiener Khintchnine theorem and interferometers

• Relaxation oscillations
• Analysis of Noise: Amplitude noise, RIN
• Wiener Khintchine Theorem and Michelson Interferometers
• Spectrometers
• Allan variance

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Litterature reference:

• Scriptum chapter 7 and 8.4

• Chapter 6.1,6.2, 6.3  Laser Physics Milonni:[Rate equations and Relaxation Oscillators]
• Chapter 13.1-13.2  Milonni Laser Physics [Coherence of Light
• Chapter 10.0, 10.1, 10.2. Optical Electronics in Modern Telecommunication, A. Yariv [Noise and  Wiener Khinchine Theorem]
• Chapter 10.8, Optical Electronics in Modern Telecommunication, A. Yariv [coherence]
• Chapter 15.5, Optical Electronics in Modern Telecommunication, A. Yariv [relaxation oscillation in laser diodes]

Content of the 6th Lecture

Shot noise, Johnson noise, heterodyne detection

Recommended Reading: 

• Chapter 10, scriptum - Optical detectors and Noise in Detection
  
• Chapter 9.3 , 9.4 , scriptum - Fiber Amplifiers, ASE Noise

Additional reading material Reading: 

• Yariv A - Optical electronics in modern communications 5ed - Oxford 1997 - Chapter 10, 11: NOISE IN OPTICAL DETECTION AND GENERATION, DETECTION OF OPTICAL RADIATION

Content of the 8th Lecture: Light propagation in fibers, specialty fibers and dispersion (GVD)

• Modes in planar infinite waveguides - rigorous solution
  
• Modes in circular waveguides (optical fibers)
  
• Fiber types - fiber manufacturing
  
• Fiber lasers: working principles
  
• Optical fiber dispersion

Required reading:

• Scriptum, Chapter 9
  

Content of the 9th Lecture

Fiber laser (cont.) : Ultra-fast lasers: basics of light pulses, mode locking.

required Reading:

• Scriptum - chapter 11: ultrafast lasers 
• Rulliere , chap 2 and 3 

additional reading (for those interested)

• synchronization of coupled oscillators

Content of the 10th Lecture

• Mode locking
• Optical frequency combs 
• Frequency metrology
• Pulse characterization

Content of the 11th Lecture

Ultra fast pulse measurement techniques: Streak cameras - autocorrelation (review), FROG technique

Content of the 12th Lecture

Non linear optics I:

• frequency conversion: sum frequency
• couple wave equation - phase matching
• second harmonic generation

Supporting book: Boyd - chapter 2

Content of the 13th Lecture

Non linear optics I:

• frequency conversion: sum frequency
• couple wave equation - phase matching
• second harmonic generation

Supporting book: Boyd - chapter 2

Laboratory visits (KLAB & LAPD)

QUIZZ # 2

Watch the mooc video lecture of Optical Parametric Oscillator (topic not in the quizz)