CONFERENCE REVIEW
Nanotechnology crosses engineering disciplines
Dan Dunn
The tenth annual conference of the American Society for Precision Engineering (ASPE, Austin, TX, Oct. 15-20) combined nanometer-scale technology aspects of optics, physics, materials science, mechanical and electrical engineering, and manufacturing technology. Of particular interest to the optics community were sessions devoted to ultraprecision machining, surface-finish measurement, precision grinding, micropositioning, and precision transducers and measurement.
Optical surfaces with a wider range of radius of curvature are being produced by nontraditional methods. Joseph P. Cunningham of Oak Ridge National Laboratory (Oak Ridge, TN) described a geometry by which single-point diamond turning can generate quasi-toroidal surfaces with radii of several meters (session I, paper #3). By keeping the blank stationary and rotating a tool in a hollow fixture, Cunningham`s grou¥has produced quasi-toroidal polystyrene laser scanning lenses (see figure).
At the other end of the radius scale, Hirofumi Suzuki of Mitsubishi Electric (Hyogo, Japan) detailed the production of tungsten carbide dies for molding glass microlenses that couple light from diode lasers to fibers (session III, paper #2). Using a miniaturized version of an otherwise familiar generation process, Suzuki has fabricated aspheres with radii of curvature less than 0.5 mm and peak-to-valley form errors less than 0.1 µm.
Papers on the laser ball bar, an integration of a heterodyne interferometer with a precision telescoping stage, demonstrated the rapid evolution of the field of precision engineering. A conventional ball bar is a metal segment of well-known fixed length, with balls mounted at each end. With triangulation techniques, the instrument is used to calibrate machine tools and other precision machinery. Because the laser ball bar telescopes, it adds speed and flexibility to the process while maintaing accuracies on the order of 3 µm over a 1-ft range of travel. Introduced only two years ago at an ASPE meeting, the instrument has become part of the standard toolbox of the precision engineer and is gaining popularity due to its robustness, range, and accuracy. Next-generation papers discussed system applications and performance.
Rosy future for engineering
Predictions by futurist Dennis Swyt for the engineering profession in the coming century highlighted a lively open-forum session. Extrapolating from historic employment patterns, Swyt predicted increased employment of the professional/ technical segment of the US work force over the next 90 years.
Dr. H. John Wood, lead optics engineer on the Hubble Space Telescope Project, presented the keynote address. After a discussion of the detection and correction of the flaw in the primary mirror, Wood presented a fascinating lecture on the latest discoveries of the telescope, relying equally on stunning photographs and simple classroom demonstrations of the physics behind the pictures.
Dr. Robert Donaldson, a familiar face in the optics community, received the ASPE`s Lifetime Achievement Award. In addition to his advances to the state of the art of measuring roundness, Dr. Donaldson, retired from Lawrence Livermore National Laboratory (Livermore, CA), led the development of the Large Optics Diamond Turning Machine, considered the world`s most precise machine tool. The late Harold E. G. Arneson also received a Lifetime Achievement Award.
DAN DUNN is an optical engineer in Danbury, CT.