Optics or photonics: what’s in a name?

07 Jan 2008

What do the terms "optics" and "photonics" mean to you? Leading researchers have had their say - and now it’s your turn.

It started off as an innocent enough question. Claire Bedrock, the publisher of Journal of Optics A: Pure and Applied Physics (and also, incidentally, optics.org), asked her editorial board whether the name of the journal should be changed to something shorter and, er, snappier.

The responses - from some of the world’s most respected optical scientists - revealed fundamental differences in perception between the terms "optics" and "photonics". Or, as Massimo Santarsiero of the University of Roma Tre put it: "This just confirms that not all of us agree on the meaning of the words optics and photonics, and surely misunderstandings of this kind would be unavoidable in the whole community of opticists (... sorry!)"

Nikolay Zheludev of the University of Southampton in the UK delved into the etymology of the words to try to tease out their true meaning:

• The Greek term όptικά (optics) referred specifically to matters and instruments of vision. Strictly speaking optics is the science of vision.

• Photonics derives from the Greek photon (fοtον), which means light. Photonics is the science of light.

"In my view, this implies that optics is a much narrower term than photonics," he concluded. "In fact, photonics embraces optics."

But Lifeng Li of China’s Tsinghua University along with several other respondents, had a very different view: "To me the term optics in the modern and broad sense means the science and technology that deals with light, and photonics is a subdiscipline of optics."

Meanwhile, Mark Stockman at Georgia State University argues that names such as optics and photonics are just tags, and their meaning does not always correspond to their linguistic roots. "Optics is conventionally used for the general science of light," he said. "Photonics was originally introduced as a counterpart of electronics - using photons instead of electrons to process and transfer signals and information - but now the meaning of photonics is gradually becoming wider."

Naturally, we’d like to know your views. Can "photonics" be used interchangeably with "optics", or do they have quite distinct meanings? Please let us know what you think by using the commenting tool at the bottom of this article.