Published Writings:

Below is a limited sampling of previously published work that includes four installments of my serial book Back to Basics, a 22-part introduction to electro-optics originally published in Laser Focus World. Back to Basics was selected as a finalist for the Jesse H. Neal Award for best subject-related series.

Also included are a feature article on astronomy and a couple of Los Angeles Times science articles on how lasers are used to trap atoms and small particles. (Arthur Ashkin’s invention of the laser light trap earned him the 2018 Nobel Prize in physics at the age of 96.)

Each article is a downloadable PDF file intended only as an example of my writing. All articles are copyright protected and are not for republication or distribution of any kind.

Back to Basics:

Sunlight and Science

The Wave Nature of Light

Creating Laser Light

The Three Phases of Lasers

Feature Article:

A New Era Dawns in Astronomy

Los Angeles Times Feature Articles:

Trapping the Light Fantastic

Capturing Atoms: First You Have to Slow Them Down

Also included below is a paper I wrote back in 2005 with my late friend E. Brian Treacy on the now famous Delayed Choice Quantum Eraser experiment, along with my 2025 rewrite. The results of this experiment have spawned many strange and fanciful interpretations, including “retrocausality,” in which it is suggested that effects can sometimes precede causes.

In our original 2005 paper, “Symmetry Sorting in a Delayed Choice Quantum Eraser,” we attempt to provide a much simpler explanation of the experiment’s results without having to invoke the quantum phenomenon of entanglement. I have since come to realize that this approach was not correct, so I have rewritten our paper to include entanglement, since it does play an important role in the experiment’s results. However, popular interpretations involving retrocausality, etc. are also wrong.

A good simplifying metaphor to use for the delayed choice quantum eraser would entail identical twins. For example, if you just now happen to notice a shared trait on one twin that you hadn’t noticed before on the other twin, you’ve made a “delayed” observation or “choice.” And because they are twins, you know that what you observe on one must also exist on the other. This is a property of quantum entanglement.

Figure 2 from our original 2005 paper depicts the delayed-choice interferometer used to sort the symmetric (a) and antisymmetric (b) radiation states of the entangled photon source (BBO) in the famous experiment by Kim et al.

The original experiment by Kim et al. did something similar (see figure above) by inducing interference among a collection of photons at one place/time and noticing (measuring) that a collection of their entangled twins, which typically displayed no interference among themselves, nevertheless  revealed interference despite being detected earlier at another location. The present is not somehow affecting the past here, as some have proclaimed, it’s only revealing to you a trait or property that was there all along but that you just didn’t (or couldn’t) see before.

Of course, the original experiment is more complicated than this, and there are other aspects to it, but it remains an elegant example of the spooky quantum property of entanglement in which the properties of multiple quanta can sometimes become correlated with one another and instantaneously act like a single quantum across space and time.

Here is a PDF of our original 2005 paper:

Delayed Choice Quantum Eraser

Here is a PDF of my 2025 rewrite:

Delayed Choice Quantum Eraser