Quakes Reaffirm Urgency of Study : Engineering: Two Irvine researchers attempt to develop a laser to determine a structure’s ability to take a jolt.

When a small earthquake rattled parts of Orange County two weeks ago, it did not damage the offices of Cecil F. Hess and James D. Trolinger. But the jolt--which measured 4.0 on the Richter scale--delivered an uncomfortable reminder of the urgency of their work.

“Every time there’s an earthquake it reminds me that we’re very unprepared to deal with them and there is a lot of work for us to do,” said Hess, co-founder and director of engineering at MetroLaser, a small Irvine start-up firm.

The company is attempting to develop a laser that would help determine a structure’s ability to withstand earthquakes, such as last year’s collapse of Interstate 880 in Oakland during a major temblor.

Toward that end, the eight-employee firm recently won a $230,000 research grant from the National Science Foundation to investigate how laser-generated holograms can be used to determine structural stability.

In a two-year study in conjunction with the civil engineering department at UC Irvine, Trolinger and Hess will attempt to determine if lasers can detect the points in any structure that are subject to the most stress from ground vibrations.

The laser would take a hologram--or three-dimensional image of a structure such as an office building--by shining a laser beam on the object and capturing its reflected image on light-sensitive glass slides.

A second hologram would capture the outline of the structure at another point in time, and the two holograms could be compared to measure the distance the structure has moved during the elapsed time.

With the data from the holograms, civil engineers would then use computers to analyze where the most pressure is exerted on a building, find its structural flaws, calculate the point at which the structure might collapse during an earthquake, and measure damage after an earthquake.

Hess said the laser technology can improve upon current test instruments known as accelerometers, vice-like devices that record the vibrations in a structure at a single point.

While it would take many cumbersome accelerometers and months of work to capture all the stress points in a large structure such as a bridge, a laser hologram could theoretically detect the stress points throughout the bridge in a single instant, Hess said.

Last year, MetroLaser proved the basic tenets of the theory in a joint research project with civil engineers at UC Irvine. In that experiment, sponsored by the National Science Foundation under a $50,000 grant, Hess and Trolinger built a laser that recorded the effect of vibrations on a liquid storage tank.

Trolinger said any equipment developed from the technology will probably be too expensive for individual homeowners to use to measure how earthquake-safe their homes are. It will most likely be used by civil engineers who must measure the safety of large structures, such as bridges, skyscrapers, hospitals or shopping centers.

Jeff Jones, general manager at San Juan Capistrano-based Endevco, a subsidiary of Allied Signal Corp. which makes accelerometers, said the laser technology sounds exciting, but he said there is still room for the current technology.

“Accelerometers will still be used for measuring small objects,” he said. “The technologies are not necessarily competing.”

It could be several years before MetroLaser markets a product, and it may be even longer before civil engineers can understand and interpret the data it produces. Its laser device, for example, may be able to identify weak spots on a bridge, but how the span should be reinforced and at what point it will collapse could take years to understand, Trolinger said.

“The technology for taking the measurements has been demonstrated,” Trolinger said. “But there’s a big gap in understanding what the measurements mean. This research is still high-risk in terms of commercial value.”

Even so, MetroLaser has lined up agreements with several companies that may be interested in manufacturing a product based on the technology: GenRad Corp., a diagnostic instruments firm in Milpitas; Physical Research Inc., a military-oriented optical diagnostics firm in Torrance; and Newport Corp., an optical instruments manufacturer in Fountain Valley.

Tom Galantowicz, president of Newport Corp., said his firm supports the direction of MetroLaser’s research and will be interested in manufacturing the instruments if the research proves fruitful.

Hess and Trolinger have searched to find commercial applications for holograms for more than two decades. Now that they believe they have found one, they are racing against time to perfect an instrument before the Big One strikes, the long-expected catastrophic earthquake.

“We’re driven by the idea that we might actually save some lives with this device,” Trolinger said.

Illuminating Flaws With Laser Light

Using holograms created by shining laser beams on an object, MetroLaser hopes to predict the eartquake safety of large structures such as a fuel storage tank.