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January 1999



New Photonics Lab Works on Sensors for Harsh Environmentsphoto in lab

Jun Wang (G) tests a sensor developed at Virginia Tech that will withstand the harsh environment in an oil well. The sensor is expected to last multiple years in full operation, as opposed to current sensors, which last only about 300 hours.


The Department has established a new laboratory to develop photonic sensors for harsh environments.

The new Photonics Laboratory, directed by Anbo Wang, currently has more than $3 million in funding, a six faculty and staff members, and 10 Ph.D. and M.S. students-with plans to add five research members this spring. The research program is supported by three laboratories.

"We do research in three major areas: fiber optic sensors for harsh environments, miniaturized 3-D imaging, and fiber components for communications and sensors," Wang said. "The sensor devices and instrumentation systems we develop are primarily for those applications where conventional sensors are difficult to apply due to the harsh environments involved. Typical harsh environments include high temperature, high pressure, high voltage, strong EMI and chemically corrosive atmospheres.

At present, the group's largest project involves developing oil well sensors with ultrahigh resolution and accuracy that can be used in harsh environments. The project is supported by a three-and-a-half-year, $2-million contract from the U.S. Department of Energy (DOE).

The project builds on the team's recent development of a self-calibrated interferometric/intensity-based (SCIIB) sensor, which for the first time successfully combined fiber interferometry and intensity-modulated devices together in a single sensor system. The sensor can withstand temperatures up to 800° C and pressures up to 20,000 p.s.i.

Sensors developed with SCIIB technology are expected to last several years in service, according to Wang. Current commercial down-hole sensors last only about 300 hours after installation, he indicated.

"With reliable sensors, oil companies can get accurate information about conditions in the wells and reservoirs, which could yield more efficient and economical oil recovery," he said.

Another harsh-environment project involves developing sensors for gas turbine engines, where high-temperature/high-pressure sensors are short-lived. "We expect our sensors to withstand higher temperatures, exhibit better reliability, and provide higher accuracy and higher frequency response," Wang said. Sponsored by Rolls Royce, Photonics Laboratory researchers are collaborating with Wing Ng, a professor of mechanical engineering.

Other sensors that the Photonics Laboratory is developing will be part of a complex system to detect earthquake-induced fires and signal the extent and location to the necessary response teams. The project is sponsored by Maryland-based InfraTech and involves researchers from a wide range of disciplines.

Equally critical are sapphire fiber sensors that the team is developing for the power industry. The project is sponsored by the National Science Foundation (NSF) and the Electric Power Research Institute (EPRI). "Sapphire is a promising material for the fabrication of optical fiber sensors," Wang explained. "It has a high melting temperature (above 2000º C), has excellent optical transmission properties, has a high hardness and elastic modulus, and is impervious to most chemicals," he added. The sensors fabricated with sapphire optical waveguides are expected to be capable of operation at temperatures above 1500º C.

Other Laboratory projects include developing special optical fibers for sensing and communications, fiber acoustic sensors for the detection and location of partial discharges in power transformers, fiber optic 3-D imaging for robot navigation, and optical fiber-based rotary communication devices for the medical industry.

Faculty members involved in the Photonics Laboratory are Wang, Ahmad Safaai-Jazi, and Russell May.

The Bradley Department of Electrical and Computer Engineering
Virginia Tech

Last Updated, May 9, 1999
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