University of Rochester

Rochester Optics Research Among Best of '93

March 5, 1994

The work of three University of Rochester scientists and engineers was cited in the December issue of Optics and Photonics News as being among the most important developments in the field for 1993.

Thomas G. Brown, an associate professor at the Institute of Optics, is working on a project that could improve the quality of semiconductor lasers. Current methods force manufacturers to produce a host of unwanted lasers just to produce a few that operate reliably at desired wavelengths. But Brown has identified a way to produce more stable lasers by microscopically changing the material through which the light waves pass.

More stable semiconductor lasers could improve CD-ROM, cable television, and computer technologies. The high costs of today's manufacturing, along with competition from computer disks and other forms of magnetic storage, currently limit the use of optical data storage. But improved stability would allow the lasers to read and write more information, a step which would make them more attractive to consumers.

Brown's colleague at the institute, Associate Professor Ian Walmsley, was cited for his work using extremely short light pulses -- a bit like flash photography -- to study atoms inside molecules. Walmsley sends into a molecule made of two atoms pulses of light that give the molecule enough energy to send out flashes of its own. Walmsley studies those flashes to study such things as the movement of the atoms.

Walmsley's work explores the boundary between the traditional realm of classical physics, which applies to everyday life, and the unfamiliar world of quantum physics, where particles such as electrons can act like waves and pass right through other objects. "The behavior of atoms can seem almost bizarre at this level," says Walmsley.

The third faculty member featured in the magazine is Stephen Jacobs, a senior scientist at the Laboratory for Laser Energetics and an associate professor at the institute, who worked with a group of scientists from Minsk, Belarus at the University's Center for Optics Manufacturing to create a new finishing method for lenses.

The method can be used to polish many different shapes of lenses, including aspheric lenses. Traditional spherical lenses create distortions that must be corrected using more spherical lenses; using a shape such as an asphere allows for a more compact design, because the extra lenses are eliminated.

The process relies upon a thick fluid with magnetic particles suspended in it. Unlike the synthetic pads and pitch usually used for polishing, this fluid is flexible, and its shape is easily changed with a magnetic field. Thus, one fluid can take several shapes, eliminating the need for several polishing tools of varying shapes. In addition, the lenses are expected to have cleaner surfaces because there are fewer polishing abrasive particles embedded in them.

The group, funded by Byelocorp Scientific Inc. and the U.S. Army, has built one machine so far and will be building another this summer. rd