From molecules to moons

Nanotechnologist Ralph E. Merkle (see www.merkle.com) has described current manufacturing methods as being akin to building a castle out of Lego blocks while wearing boxing gloves. "You can push the Lego blocks into great heaps and pile them up, but you can't really snap them together the way you'd like," he writes. Nanotechnology manufacturing is about taking off the gloves and arranging the blocks (atoms or molecules) whichever way we want—a process that should eventually lead to many new materials with properties previously only dreamt of.

Among the many challenges involved with advancing nanotechnology manufacturing is developing the ability to manipulate matter on a molecular and atomic scale and to visualize the resulting nanoscale structures. One tool that can do both is the atomic-force microscope, which has come a long way since its invention in 1986 (see p. 87).

You can find out more about nanotechnology by attending this year's Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference (CLEO/IQEC; San Francisco, CA) in May. The OSA (Washington, D.C.) will launch a new meeting alongside CLEO/IQEC. Photonic Applications, Systems and Technologies (PhAST) will offer symposia including one on photonics in nanotechnology. For a preview of both conferences see p. 105.

Of course, even the most current advances in optoelectronics are not limited to the nanoscale. The idea of microsensors or displays embedded in "smart fabrics" has been around for some time. Such sensors could make the fabric sensitive, for instance, to IR radiation or pressure. In a step toward making such fabrics a reality, microbolometer detectors have been fabricated on flexible substrates that exhibit performance similar to those made on rigid silicon substrates (see p. 99).

And on an "astronomical scale," enhancement of the performance of wavefront sensors in adaptive optical systems is improving image coherence and enabling the coupling of large optical telescopes into interferometric arrays. Large optical interferometers, previously only feasible for small, specially designed telescopes, have become a reality. Images of Jupiter's moon Io on our cover demonstrate the benefit of a telescope-based adaptive optical system—a review of the state of adaptive optics and wavefront sensing by senior editor Hassaun Jones-Bey begins on p. 77.