What to expect from Laser Physics?
A nice view of modern optics has it that the subject of optics began afresh with the invention of the laser. We'll take the laser as a pivot-point, and look backwards from its invention to the classical optics needed to understand how the laser tailors light, and forward to the quantum optics explosion that has followed. We'll study: interference, diffraction theory, gaussian beams, laser resonators, semiclassical laser theory, and ultrafast pulse generation. In group presentations, we'll also review a selection from the remarkable range of currently active research topics: laser cooling, photonic bandgap structures, extreme optics, quantum information and other topics.
The course should be considered a subject of basic physics literacy, particularly in optics.

Basic information (see also course handout)
  • Textbook
“Laser Physics" Milonni & Eberly (Wiley 2010); this is available in the Bookstore.
Modern Optics Notes” 2010 — adjunct material: PDF of old version of course includes some background material, much laser physics, but not as much laser physics as in Milonni & Eberly

  • Recommended purchase (in general, also for other courses!)
"A Student's Guide to Fourier Transforms", J.F. James, a small paperback
(2002 printing ~$23 Amazon.ca, cheaper than 1995 printing)
Other reference material is described in the
course handout
  • Lectures: M, R 10am MP606 [I'm working on getting a better room, one that we can darken for demos…]
  • Prof. Robin Marjoribanks
  • marjphysics.utoronto.ca
  • Office: MP1104C
  • office hours: TO BE CONFIRMED IN 1st LECTURE Thursdays 2-3 pm usu. MP021 (basement lab, 180° around behind Tower elevators)
  • Vijin VENU
  • vvenu physics.utoronto.ca
If you have concerns about marking, first see the marker.
The recommended texts are on reserve in the Physics Library, and at Gerstein Science Library.

Special Dates
*Double-check dates at Faculty of Arts & Science*
September 19 - Last day to add courses with F and Y section codes via ACORN
October 31 (latest) - Examination timetable for F section code courses posted
November 5 - Last day to drop F courses without academic penalty
November 5-9 - Fall Reading Week
December 5 - Fall classes end

Problem Sets & Midterm Dates (links will work once items are posted)

Problem sets are handed in to the Drop Box (#25 PHY485/1485), basement floor stairwell opposite elevators, by 5pm on the day due. Please keep a photocopy of anything handed in.
PS#1 - out 17 September, due 1 October, Solutions to PS#1
PS#2 - out 4 October, due 18 October, Solutions to PS#2
Midterm Test: (
to be confirmed) Tuesday 23 October 2018, 6-8pm; examples: Midterm2004
Solutions to MT2018
PS#3 - out 29 October, due 19 November, Solutions to PS#3
PS#4 - out 22 November, due 5 December (note: Faculty rules prohibit extensions beyond last day of term) Solutions to PS#4
Seminar Day: (to be confirmed) Monday 26 November, 4pm-6:30pm
Final Exam to be announced: http://www.artsci.utoronto.ca/*****


Reading in Milonni & Eberly

Here is advice about reading in Milonni & Eberly: our text isn’t the only book to cover our material, you may prefer another.

  • to be posted as lectures begin

Demo Postings: some of these are old and may need updating/fixing

Diffraction Demo (Java applet; open “index.html” in your Java-aware browser) This gives quite a good ‘feel’ for diffraction.

Dispersion Primer (sent by email)

Resonance Demo (
Polarization Demo (
Note that these require downloading the FREE LabVIEW 7.1 Runtime Engine from National Instruments. This means you don’t have to own LabVIEW 7.1; you need a different engine for Windows/Mac OS X/Linux.

Lecture Notes
Most materials © RS Marjoribanks, 2018.
Some parts of these notes are adapted or taken from materials made available by Professor Rick Trebino at Georgia Tech -- he's done a wonderful service! Please don't distribute these notes further, they are © R Trebino, used by permission.
(Links will only work once lecture notes have been uploaded.)

Lecture 0 – Organizational lecture: dates for midterm, problem sets, seminar presentation
Lecture 1 – A laser needs a resonator and a gain medium: multiple examples of resonators, acoustic example, photon’s viewpoint
Lecture 2 – A laser needs a resonator and a gain medium: gain medium – initial review of origin of index of refraction, materials fields, two-level systems
Lecture 3
Lecture 4
Lecture 5 – have a look also at this video of using an IR card, for some interesting connections to fluorescence:
Lecture 6
Lecture 7
Lecture 8
Lecture 9
Lecture 10
Lecture 11
Lecture 12
Lecture 13
Lecture 14
Lecture 15
Lecture 16
Lecture 17
Lecture 18
Lecture 19
Lecture 20

Extra material: links, illustrations and comments

Gaussian beams:
Here are some good online calculators for gaussian beams — useful in the lab, and they may give you ideas for your problem set, but won't really help you solve anything:



This software, however, will let you do much more and set up systems of multiple elements:


These will also let you solve for eigenmodes — gaussian beams trapped within a cavity:


Quick and efficient tutorial here:

Flashers & coherence: This demo has members of class with LED lights, which they flash and synchronize to the rhythm I beat out — a little like an optical field can drive a number of Lorentz radiators. When I stop, though, they quickly dephase and become nearly randomized — they 'forget' their relative phase. I can plot number of flashers ON in each frame, and the oscillations make a kind of fringe with a fringe-visibility. I hope this will help give you an intuition for coherence, partial coherence, and incoherence: Flashers1-2008

Time-domain interferometry: these videos illustrate one question from PS#3, in which you found the spectrum of two pulses from a laser. In time, these two pulses are analogous to two slits in space: in space, the diffraction pattern is the far-field diffraction pattern (a Fourier transform, then intensity is the square modulus), while for two pulses the Fourier transform and square modulus gives the power spectrum in frequency. Both of these of course make fringes! Two pulses farther apart in time give finer fringes in spectrum, just as two slits more separated make finer fringes in space. These data from from a 100-fs fiber-laser experiment I put in place for the advanced undergraduate laboratories (which is right this moment being upgraded).

Time (oscilloscope):

Frequency (optical spectrum analyzer):

MIT videos:


Collection of some student questions, and answers



Last revised: 12 September 2017 -- © R.S. Marjoribanks