Rank Prize rewards optics pioneers

17 Jun 2002

Today, inventors of the VCSEL, optical coherence tomography and fiber Bragg gratings receive recognition.

Rank prize

This year's winners of the Rank Prize for Optoelectronics are the inventors of the vertical cavity surface emitting laser (VCSEL), optical coherence tomography (OCT) and fiber Bragg gratings. Rewarding significant advances in optoelectronics, the prize comes from a USD 1.8 million fund that was donated by The Rank Foundation in 1972.

Japanese researcher Kenichi Iga, and US researchers Robert Burnham and Donald Scifres will share USD 54 000 for their pioneering work on VCSELs.

In 1979 while working at the Tokyo Institute of Technology, Iga developed a semiconductor laser that emitted coherent light through the wafer surface. Two metallic mirrors, deposited onto the top and bottom surfaces of the wafer, formed the laser's vertical cavity.

At the same time, Burnham and Scifres, then at Xerox, US, developed a semiconductor structure that was based on a Fabry-Perot optical cavity. The cavity was located transverse to the wafer plane.

For the high-reflectivity mirrors, Burnham and Scifres suggested using distributed Bragg reflectors made with different alternating semiconductor layers. In this way, they had anticipated the essential features of today's VCSELs.

US researchers James Fujimoto, Eric Swanson and Carmen Puliafito have won USD 57 000 for inventing the biological imaging technique, optical coherence tomography (OCT).

Fujimoto first developed the OCT technique at Massachusetts Institute of Technology in 1991, by exploiting low coherence interferometry. He then went on to work with Swanson, also at MIT and Puliafito, then at the New England Eye Center, to develop the first OCT instrument.

OCT non-invasively images biological structures such as the retina and lens of the eye and more recently the coronary artery and gastrointestinal tract. The first ophthalmic diagnostic product based on OCT was introduced in 1996 and OCT is now used in eye clinics worldwide.

Canadian researchers Ken Owen Hill and Brian Garside, and US researchers Gerald Meltz and William Morey share USD 57 000 for inventing and developing practical fiber Bragg gratings.

Working at the Center for Communications Research in Ottawa in 1978, Hill discovered with time, optical fibers that transmit visible laser light eventually reflect the light at the laser's wavelength. He concluded that the laser light imprinted a standing wave pattern or grating on the photosensitive fiber at regularly spaced planes.

Later in 1981 at Canada's McMaster University Garside showed that visible light imprints the grating via a two-photon effect. Meltz and Morey, while at United Technologies Research Center in 1989, rapidly imprinted gratings by shining a striped pattern of ultraviolet light onto a fiber. By generating striped patterns with light interference, the researchers went on to develop Bragg gratings that reflected light of any wavelength.