Across the world, one encounters the idea that an important goal for postgraduate education is the training of the “next generation of leaders”. When academic and research centers list their goals, one will almost always find the training of “leadership” among them. As with just about every instance where an […]
Read More…And the Light Shattered
Conventional definitions of geometric phase are wrong
[Note that I am going to use definition examples below from two authors that I respect and whose work I genuinely appreciate, so I have no intention of disparaging them. However, I do regard the current situation as an embarrassment for anyone who has spent time working in geometric phase. […]
Read MoreThe difference between a mathematical model and a physical model: the problem with geometric phase theory
In the past few years I have spent a significant amount of my research time on a narrow corner of physics called “geometric phase”. [1] And in discussions with colleagues I have many times mentioned the difference between a mathematical and a physical model, and how disappointed I am to […]
Read MoreRefraction angles for interfaces with absorbing media interfaces
For light entering an interface from region 1 to region 2, where region 1 is a dielectric medium with refractive index $n_1$, and region 2 is an absorbing medium with complex refractive index $n_2 = n_2 + ik_2$. In a dielectric-dielectric case, the angle of refraction $\theta_2$ is given by$$\sin […]
Read MoreThermal footprints
With a good thermal infrared camera, we can explore phenomena that produce only small thermal changes in the environment. One example is the temperature change produce by our footprints when walking. When a shoe or foot contacts the floor, the floor is usually the cooler surface, and so the shoe […]
Read MoreUsing polarization vision to minimize reflection glare
For some of my class lectures, I wanted to improve on the images that I’ve been using to illustrate the different uses for optical polarization in the world. One very simple application is to use a linear polarizer to remove reflection glare, from a water surface or from a pane […]
Read MoreHuman infrared vision
When describing the visual spectrum range, most researchers (including myself) will describe it as spanning 400-700 nm, using round numbers as a convenience. Some will use the narrower region 420-680 nm, allowing only for the region where the eye’s sensitivity is reasonably high, while some use the expanded region 380-720 […]
Read MoreIntroduction to the blog
Ever since I was a graduate student, I’ve spent time writing notes on technical articles and blog posts that I’ve found interesting. I tend to get interested in a lot of different subjects, and so these notes wander among the fields of mathematics and algorithms, optical design and optical physics, […]
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