ECE455
ECE455 (Optical Electronics) is a 3/4-credit-hour course that satisfies the Technical Elective requirements for ECE majors. It has traditionally been offered in Spring semesters, the most recent being Spring 2021 and Spring 2023, but is currently offered in Fall 2024.
Content Covered
This course focuses solely on lasers. There are two essential components for a laser: a resonant cavity and optical gain. The first third of the course starts off with resonant cavities, including ray tracing, ray matrices, and how the light is distributed through the cavity. The second third of the course deals with the optical gain: lineshapes, absorption, saturation, threshold, laser dynamics, 3-4 level systems, Q-switching and mode-locking. There is typically a second midterm on this material. The final third of the course is on particular lasers, including: tunable lasers, rare-earth-ion lasers, gas-discharge lasers, non-linear processes and semiconductor lasers.
Prerequisites
ECE350 (Fields and Waves II) or PHYS436 is the only prerequisite listed, however it is a fairly loose requirement. Since many graduate students without prior experience in E/M take this course, it will suffice to just have PHYS212 (University Physics, Electricity and Magnetism) or ECE329 (Fields and Waves I).
When to Take It
If you are interested in lasers, this course is essential. Don't be fooled by the title "Optical Electronics." This class should instead be called "Laser Electronics." It was last offered in Spring 2021 and Spring 2023, but is now offered in Fall 2024. If this course interests you, look out to see when it is offered and try to complete 329 (and ideally, if possible) 350 in preparation for this course.
Course Structure
In the recent past there have been two midterms (down from three). One on the first third of the class, and the second on the second third of the class. In place of a final exam, there is a research paper due. It is typically a 15-20 page report on any hot topic in laser engineering that you find interesting. Graduate students (or undergraduates who take the class for 4 credit hours) are also expected to present their paper for the extra credit they receive. These papers and presentations are taken very seriously, and students are expected to prepare and deliver them in an academic conference style format. The homework is challenging, but very reasonable, and certainly doable given the lecture notes and book material. Homework will typically take about 5-6 hours a week (there are usually 8 assignments in a semester). There is a "homework final" at the end of the course that presents a complete laser design problem. This problem will test your knowledge of all of the topics covered in lecture, and will take more effort and time than a regular assignment to prepare for. Office hours are incredibly important for adequate understanding and completion of the homework, as the TA generally goes over problem solving methodology (which is not covered as in depth in the lecture). The exams are relatively fair, assuming you've read the book, understood the lectures and can do the homework yourself. Typically, exams from the previous 5 years are posted (minus the solutions). Again, office hour attendance helps tremendously with exam preparation. The class is generally taken by large amounts of graduate students from all STEM majors. Grades are curved at the end of the semester (graduate and undergraduate combined), so in order to do well, it is important to stay on top of the material. Because none of the material is very hard to comprehend, exam averages are usually high.
Instructors
The past three offerings (including Fall 2024) have been taught by Professor Peter Dragic.
Life After
If you are interested in semiconductor lasers, ECE304 or ECE495 may be a good choice for some photonics theory and lab work. The semiconductor fundamentals would also be key, taught in ECE340, ECE441 and ECE488. If you're interested in gas lasers, Prof. Eden teaches a follow-on graduate level class ECE523, or if you prefer to stick to the semiconductor variant, check out ECE535.