Toward white light
Optical fiber has undergone incredible transformation over the past decade, with modifications to the physical design, fabrication techniques, and materials all contributing to big improvements in performance and flexibility, while opening up some exciting new applications.
Optical fiber has undergone incredible transformation over the past decade, with modifications to the physical design, fabrication techniques, and materials all contributing to big improvements in performance and flexibility, while opening up some exciting new applications. Telecommunications is the largest market for optical fiber so silica fiber optimized for this application is now ubiquitous and inexpensive. But other fibers can be more appropriate in some situations. Conventional fiber passes light through a solid core confined by a lower-index outer cladding. Changing the core or cladding material can tailor a fiber to meet specific needs—silver halide for the mid-infrared, for instance. More recent advances involve passing the light through a hollow core surrounded by a periodic matrix of holes that forms a photonic-bandgap material. These photonic-crystal fibers (PCFs) promise exciting new applications: the combination of tailored nonlinear PCF and compact, high-power ultrafast fiber lasers produces a true white-light continuum (see cover and p. 59).
Specialty-fiber advances also are occurring on other fronts. Fabricating optical fiber from polymer adds flexibility and robustness. Typically used in short-distance medium-bit-rate applications, polymer fiber is benefiting from advances set to extend its range of applications (see p. 73). You can find out about other optical-fiber developments by participating in a live Webcast with contributing editor Jeff Hecht on Nov. 19. Part of his continuing “Fundamentals of Photonics” series, this event will cover specialty optical fibers—find more details at www.laserfocusworld.com/webcasts/index.html.
In July I mentioned that the Internet is changing the world of publishing—an understatement, and one that’s especially true for reporting the news. Getting news into print takes time. So this month we are discontinuing the monthly “Industry Reports” section and instead will be covering the markets and business of photonics online every day. Of course we’ll continue our trademark in-depth coverage of global photonics technology news: in print and online at www.laserfocusworld.com.
Stephen G. Anderson
Associate Publisher/Editor in Chief