Sometimes, writing about developments in photonics feels a bit like the fraught line from novelist William Faulkner: “The past is never dead. It’s not even past.” And I mean that in a good way!

Not only is the science and technology of optics and photonics linked to the ancient laws of physics, but the related applications ranging from communications and medicine, to manufacturing and imaging have a long history. And advances in understanding and capabilities keep building from one generation of products and applications to produce the next.

A new generation of products may result from simply adding new components to a system, as has happened with Raman spectrometers. As described in a feature by senior editor John Wallace, because of component advances spurred by the telecommunications boom, Raman spectroscopy has become more accessible, less expensive, and more sensitive (see article). Likewise, in the case of flow cytometry, first commercialized in the late 1960s, the introduction of green laser diodes to replace DPSS lasers is now enabling lower-cost, more portable products, as explained by an engineer from Osram (see article).

The echoes from the ongoing telecom boom can also be heard in two other features. The first, from engineers at Huawei Technologies Canada, describes how software can optimize thermooptic silicon photonic switches via numerical analysis (see article). And the second, from researchers at DTU Fotonik, explains how the communications bandwidth of a single optical fiber can be greatly extended by on-chip mode-division multiplexing (see article).

Finally, old problems like correcting vision can be solved by new, less-invasive approaches that use established technologies—in the case of our cover story, ultrafast laser micromachining changes the refractive index of ophthalmic materials through nonlinear interactions (see article). The article is by Wayne Knox, a professor at the University of Rochester, who himself had a long history in telecommunications. Personally, I like the past and the way it keeps reverberating around us.

(From: https://www.laserfocusworld.com/articles/print/volume-54/issue-03/columns/editor-s-desk/photonics-always-new-again.html)