Physics 106c

In spring of 2021, the second half of Ph 106c will cover optics. The first half, to be taught by Prof. Sunil Golwala, will cover advanced topics in electricity and magnetism.

The official course website is hosted on the Caltech Canvas [Caltech access only]. Some information is summarized below, but be sure to check the official website for the most current information.

Click here to view a preliminary syllabus


Lectures will be offered via Zoom at a link that will be posted in the last week of April (the last week of Prof. Golwala's lectures). They will be offered at the same time (MWF 11:00-11:55 am), but will also be recorded. All lecture notes will be made available.

The lectures will not follow a particular book. Readings will be posted for the lectures, most of which will be drawn from the list of suggested books below.


The total grade will be determined by 50% from the first half, and 50% from the second half. Specifically, 25% homework from the first half, 25% midterm covering material from the first half, 25% homework from the second half, and 25% final covering material from the second half.

Problem Sets

There will be four problem sets for this half of the course, which will be in total worth 25% of your overall 106c grade. Collaboration is strongly encouraged.

Problem set collaboration policy, short version: Open everything. All work must be your own, and you must indicate what/whom you consulted. Longer version: You are free to consult any textbooks, online resources, people, etc., However, everything submitted must be your own work that you understand and show, and you must indicate any resources/people/etc. that you consulted. Include printouts of any computer code that you used. This policy applies only to the problem sets; there is no collaboration on the final exam.


Students get one “silver bullet” extension for all of Ph 106c (i.e. you don’t get one for each half). Otherwise, extensions will only be granted only for health, family, emergency, religious, or other approved reasons. Ask as much in advance as possible; I do not check email late in the evenings so a last-minute request might not be seen in time. Remember that you can always reach out if you are having trouble.


The final will focus only on optics. Since optics draws heavily on the first half of 106c (and all of 106b), you are responsible for being familiar with it. However, the problems will be similar in material to the homework and lectures from the second half only. The final will count for 25% of your total grade for 106c.

The final exam will be take-home and time limited. Details will be posted in mid-May. Collaboration is not allowed. You may use any materials posted on the course website, including lectures, notes, and readings. You may also use any notes/work that you have produced by typing or writing up. However, you may not use other resources.

Honor Code

“No member of the Caltech community shall take unfair advantage of any other member of the Caltech community.” This applies to all aspects of this course.

Inclusion and Accessibility

Everyone is welcome in this class and at Caltech, and everyone is responsible for creating a welcoming environment. Please contact us with any concerns, or if any accommodations are needed.

Learning Outcomes

The main goal is to gain intuitive and mathematical understanding into how light and optics are used for scientific research and in everyday life. Students will:

    • Apply physical and mathematical reasoning to understand the behavior of light, both in free space and when interacting with media.

    • Understand how the study of classical optics arises from electromagnetic theory, in particular topics covered in Ph 106b and the first half of Ph 106c.

    • Learn about the action of basic optical elements such as lenses, mirrors, and waveplates, and use that knowledge to design and understand complex optical systems.

    • Understand the origins and manifestations of the wave-like nature of light

    • Be able to apply both geometrical and wave optics concepts, while understanding the advantages and weaknesses of each approach.

Approximate Course Outline

Because this is a new course (and a wacky term), the outline might change based on the realized pace, as well as student interests and feedback. Please give plenty of feedback!

Ray Optics – The physical and mathematical interpretation of light rays, matrix description of light propagation in simple and complex systems, simple image formation.

Modes and Waveguides – Optical modes, Gaussian optics, resonators and cavities, fiber optics.

Wave Optics – Wave equations, interference, diffraction, coherence, Fourier optics, polarization.

Advanced Topics – To be decided, but possible topics include aberrations, modulators, quantum electronics, and non-linear optics.

Suggested books

There are no required books, but here are some to which I will refer often and should be on electronic reserve in the library. Readings from books will be posted online in addition to the books being available electronically through the library. The “most important” books are listed below, in approximate order of how often we will be using them.

Steck, Classical and Modern Optics. A great book that covers most of the material and in roughly the same order. Available for free on Prof. Steck’s website,

Brooker, Modern and Classical Optics. Very clear and concise overview, though it doesn’t go into much depth on many topics.

Siegman, Lasers. The focus is, not surprisingly, on lasers, but it has very clear and practical discussions of many relevant topics.

Born and Wolf, Principles of Optics. This book is “The Jackson” for optics. Tremendous depth, detail, and rigor, though not always the best way to be introduced to a particular subject.

Thorne and Blandford, Modern Classical Physics. Part III focuses on optics and was previously the basis for a component of Ph 136. This book is written at a very high level and offers deep and profound discussions. It is highly recommended for those with an inclination toward theory.