Challenges of change
Not so long ago, when purchasing a television set, most consumers took little interest in the technology behind the TV display itself because the cathode ray tube was ubiquitous.
Not so long ago, when purchasing a television set, most consumers took little interest in the technology behind the TV display itself because the cathode ray tube was ubiquitous. Today, though, consumers wanting to purchase a new TV are faced with a potentially bewildering set of choices that have emerged from a variety of parallel technological approaches to produce an appealing and cost-effective product. Even more options emerged this year in January with Mitsubishi’s announcement that a commercial laser-based TV will be on the market by the end of 2008 and Sony’s launch of an 11 in. organic LED-based TV. Displays based on OLEDs are currently of particular interest because they are considered “green” technology. They use less power than LED devices (no backlighting is required) while apparently offering better picture quality. Cost-competitiveness of OLEDs remains something of an issue, however. Among the approaches to reducing production costs is a hybrid process that combines vapor deposition and solution processing (see cover and page 57).
Few consumers would think about nonlinear optics when purchasing a pair of sunglasses with photochromic (or “transition”) lenses. But such lenses do exhibit nonlinear absorbance, as do many other materials. And among the current challenges for nonlinear optics researchers is “turnkey” characterization of the nonlinear absorption spectrum of such materials over a wide bandwidthsomething that is now being made feasible by the advent of spectrally bright femtosecond white-light continua (see page 77).
Meanwhile, development of nonlinear optics applications based on gas-phase materials has been hampered by lack of a practical and relatively compact means to confine gases and guide light in a single mode over extended interaction lengths. Now state-of-the-art photonic-crystal fibers use a length of gas-filled hollow-core photonic-crystal fiber sealed to a conventional fiber, and are enabling high nonlinearity at low light levels with applications in fiber lasers and frequency combs (see page 61).
Stephen G. Anderson
Associate Publisher/Editor in Chief