ECE 455

• Microelectronics and Photonics

To introduce the student to the generation, propagation, and detection of optical electromagnetic waves.

• Optical beams and cavities: Review of electromagnetics, ray tracing, ABCD matrix, stable cavities, Gaussian beams, resonant cavities
• Interaction of Photons and Matter: Blackbody radiation, Einstein coefficients, lineshape functions, gain, absorption, saturation
• Basic Laser Theory: Threshold gain, laser oscillation, steady-state and dynamic systems, Q-switching, mode-locking
• Laser Systems: 3- and 4-level lasers, rare-earth-ion lasers, broad-band-gain, tunable lasers, gas discharge lasers
• Nonlinear processes and harmonic generation
• Semiconductor lasers: Review of semiconductor fundamentals, absorption, gain, oscillation, optical modes
• Final project presentation

To introduce the student to the generation, propagation, and detection of optical electromagnetic waves.

Topics:

• Optical beams and cavities: Review of electromagnetics, ray tracing, ABCD matrix, stable cavities, Gaussian beams, resonant cavities
• Interaction of Photons and Matter: Blackbody radiation, Einstein coefficients, lineshape functions, gain, absorption, saturation
• Basic Laser Theory: Threshold gain, laser oscillation, steady-state and dynamic systems, Q-switching, mode-locking
• Laser Systems: 3- and 4-level lasers, rare-earth-ion lasers, broad-band-gain, tunable lasers, gas discharge lasers
• Nonlinear processes and harmonic generation
• Semiconductor lasers: Review of semiconductor fundamentals, absorption, gain, oscillation, optical modes
• Final project presentation

• A course in electromagnetic theory including wave propagation
• A prior course in the physics of electronic devices

J. T. Verdeyen, Laser Electronics, 3rd ed., Prentice-Hall.

W. Silfvast, Laser Fundamentals
A. Yariv, Optical Electronics

Engineering Science: 2 credits
Engineering Design: 1 credit

The goals of this course are to enable the students to gain a fundamental understanding of the basic physics and technology of quantum electronics devices and laser systems. These fundamentals include optical beam propagation in free space, in media and in cavities, interaction of electromagnetic radiation with matter, the creation of population inversions in various media, and the design of laser systems. Upon mastery of these fundamentals, students should be able to design simple laser systems. As this course is offered to both senior undergraduate and graduate students, the course has the additional goals of providing graduating seniors with sufficient background in laser systems to pursue career opportunities or to pursue graduate studies in the laser field; and of providing graduate students with an introductory course in laser systems to pursue further graduate studies in the field.

Upon completion of the instructional units on optical beam propagation and optical cavities, students should be able to:

1. Perform ray tracing of beams through optical elements using the ABCD matrix formulation. (1,6)

2. Assess the stability of optical cavities and design optical cavities having specified characteristics using the ABCD matrix formulation. (1,6)

3. Identify, characterize and predict the properties of fundamental and higher order Gaussian optical beams. (1,6)

4. Propagate Gaussian beams through optical systems. (1,6)

5. Assess the stability of optical cavities and design optical cavities having specified characteristics when the electromagnetic waves are Gaussian beams. (1,2,6)

6. Compute the resonant frequencies of Fabry-Perot etalons for plane waves, and cavities having spherical mirrors for Gaussian beams. (1,6)

7. Assess the consequences of a cavity having gain. (1,2,6)

8. Use spreadsheets, programs such as Matlab or Mathematica or write computer programs to perform parametric or design studies based on these principles. This objective applies to all instructional units. (1,6)

9. Respond to open-ended questions from the instructor on these principles. This objective applies to all instructional units. (3)

Upon completion of the instructional units on the interaction of optical radiation with matter, students should be able to:

10. Identify the properties of black-body radiation and calculate its power spectrum. (1,6)

11. Assess the dominant line broadening mechanisms of radiative transitions and calculate their lineshape functions. (1,6)

12. Use the lineshape function to compute Einstein A and B coefficients, and the stimulated emission cross section. (1,6)

13. Given properties of an optical cavity or optical system, compute the threshold gain and design cavities or optical systems having specified threshold gains. (1,2,6)

14. Solve simultaneous partial differential equations for the densities of atomic levels given pump conditions to obtain the inversion density, and compute the gain or absorption of laser media. (1)

15. Calculate the saturation intensity of laser media for homogeneous and inhomogeneous broadening. (1,6)

Upon completion of the instruction units on laser oscillation and efficiency, students should be able to:

16. Predict optical output intensity and efficiency of a continuous wave laser given the atomic properties, energy level diagram, and optical cavity parameters. (1,6)

17. Design a simple continuous wave laser meeting given performance specifications. (1,2,6)

18. Predict the optical output power and pulse length of a Q-switched laser. (1,6)

19. Design a simple Q-switched laser. (1,2,6)

20. Explain the principles of mode-locking, and use those principles to predict the repetition rate and optical pulse length of a mode-locked laser. (1,3,6)

Upon completion of the instruction units on laser systems, students should be able to:

21. Identify and explain the principles of operation of 3- and 4-level lasers and optically pumped rare-earth ion lasers. (1,3,6)

22. Identify and explain the pumping and excitation mechanisms of gas lasers. (1,3,6)

23. Identify and explain the fundamental properties of tunable lasers and lasers which have broadband gain. (1,3,6)

24. Use the capabilities developed in previous instructional units to design specific laser systems, such as optically pumped rare-earth ion lasers, and extrapolate these concepts to the design of related laser systems. (1,2,6)

25. Explain the principles of harmonic generation using nonlinear crystals, and perform simple calculations of the conversion efficiency of fundamental frequencies to the second harmonic. (1,3,6)

Upon completion of the instruction units on semiconductor lasers, students should be able to:

26. Explain the differences and similarities between lasers based on transitions between discrete atomic or molecular levels, and semiconductor lasers. (1,3,6)

27. Explain the principles of gain and absorption in highly doped homojunction laser diodes operating with high-levels of injection current. (1,3,6)

28. Use the concepts of densities of states, quasi-Fermi levels, Fermi distributions and simple semiconductor energy band theory to compute gain vs frequency as a function of injection current in a homojunction laser. (1)

29. Predict the laser spectrum of a homojunction laser. (1,6)

30. Design a simple diode laser having given performance specifications. (1,2,6)

31. Explain the fundamentals of heterojunction and quantum-well semiconductor lasers. (1,3,6)

Upon completion of all instruction units, students as a final project should be able to:

32. Analyze current laser systems, as researched from the literature, in terms of threshold gain, pumping mechanisms, laser output power, efficiency and modal quality. (1,3,4,6)

33. Design a simple laser system given material properties and desired operating parameters such as power, modal quality, pulse length and efficiency. (1,2,3)

34. Make a presentation to the class or compose a final report detailing the analysis or design, and answer questions to justify the analysis or design. (3)