Originally Published: Feb 23, 2018 @ 11:36

This article defines the word photonics and explains the origin of the word.

Before getting into a definition of photonics, we first have to define what a photon is. The word “photon” has been in use for over a half-century, but even today, trying to nail down a technical definition of a photon quickly spirals into abstract particle physics, and that’s not useful from a business perspective. A practical definition of a photon is this:

Photons are sub-atomic particles that are the fundamental building blocks of light in the same way that electrons are the fundamental building blocks of negative electric charge.

The origin of the word photonics can be traced to a 1974 conference in France called, appropriately, “Photonics.” At the meeting, an international cross-section of specialists set out to define a growing area of research that, up to that point, was ambiguously named (and inconsistently hyphenated) as either electro-optics or opto-electronics. The conference was meant to settle the terminology and be “the birth certificate for a new technological field which will certainly be developed in the near future.”The conference proceedings, which were edited by M. Balkanski and P. Lallemand, are not available online, although I have ordered a print copy.1 Fortunately, in the meantime and thanks to the resources at the University of Rochester’s Physics, Optics and Astronomy library, I tracked down a print copy of an English translation of a Russian review of the French conference. (You should be impressed by that.) The summary article was written by P. Feofilov in Optical Spectroscopy a Russian journal translated into English by the Optical Society of America.

Source: “Photonics. Edited by M. Balkanski and P. Lallemand. Gauthier-Villars, Paris, 1975, 412 pp.”, reviewed by P. Feofilov, Opt. Spektrosk. 40, 204?205 (January 1976).

I have attached a photocopy of a portion of Feofilov’s article. In it, he gives what might arguably be called the “definitive definition” of photonics.


The editors use photonics (by analogy with electronics) to denote the phenomena and devices in which information is carried by photons (the role played by electrons in electronics)… The necessity for outlining a new field arises because the development of semiconductor lasers, fiber optics, and highly sensitive rapid radiation detectors has opened the way for different and very promising methods of constructing new optical devices, primarily for utilization in optical communications and for recording, storage and processing of optical information.

Merging all that information, we can construct the following practical definition of photonics:

Photonics occupies a region of intersection between the fields of optics and electronics that is devoted to using photons to communicate, record, store, and process optical information in analogy to the way that electrons are used in electronics.

I would be remiss if I failed to note the enormous contribution of the scientist Herwig Kogelnik in popularizing the word photonics. Kogelnik, a pioneering scientist from Bell Labs, was one of the preeminent attendees at the Photonics conference. In 1982, at the Conference on Lasers and Electro-Optics (CLEO), Kogelnik presented an invited paper titled “Optics and photonics: electrooptics for the Eighties.” That talk seems to have been hugely influential in establishing the word photonics as the official name of the new field.

1I now have a copy of Photonics. Balkanski describes the book as “almost a birth certificate for a new technological field which will certainly be developed in the near future.”

That certainly was not an understatement!

In the preface, Balkanski writes:

The word photonics is used throughout by analogy with electronics, to designate all functions where a photon rather than an electron is the information vehicle.