Laser surveillance unlikely, expert says

See also my post “Mecham complained 26 years too early about laser beams.”


January 23, 1988

By Carle Hodge
Arizona Republic Science Writer

A surveillance specialist says using a laser to eavesdrop on Gov. Evan Mecham would be possible but improbable.

Less expensive, easier ways exist for furtively tuning in on conversations, Forrest M. Mims III said Friday.

And because laser beams penetrate glass but not concrete, it would be difficult to fire them into the governor’s office, the Seguin, Texas, author and consultant said.

Such an act also would be illegal, Mims said. Federal laws forbid making or even owning a laser device intended for bugging.

Earlier this week, Mecham said evidence of laser spying had been uncovered in his office and his home. State Rep. Jim Ratliff, R-Sun City, said the governor has a transistor radio that resembles a Coke can that the governor said he used to deflect laser beams.

Mims, told of that, said, “What? That doesn’t make any sense.”

A transistor radio might be modified to detect laser light but would not be able to deflect it, he said.

In addition, because laser beams move only in a straight line, an intruder using them would have to be level with one of Mecham’s ninth-floor windows, Mims said, and the laser would have to be activated within a mile.

There are no other buildings that tall near the Capitol.

Mims said a laser aimed from ground level into a first-floor window “will bounce back into you face, but if you shine it onto the ninth floor, it’s going to bounce (at an angle) off into space.”

Lasers send enormously concentrated streams of intense light at specific wavelengths.

Alexander Graham Bell discovered the principles of light-wave communication in 1880, but no workable way was found to use it until the 1950s.

In the Mecham scenario, a laser would detect differences in vibrations in window panes caused by sounds inside a room.

Depending on the thickness of the glass, individual voices could be distinguished at the beam’s source by using “a light detector and any ordinary amplifier,” Mims said.

It is even possible, he said, to recognize other noises within the room, such as the flight of a fly.

“It’s like a telephone,” Mims said. “In your headset is a thin metal plate called a diaphragm, and when you talk, the diaphragm resonates.”

The diaphragm would be equivalent to the window off which the laser light was bounced. But the signal still would need to be amplified when it returned to its source.

Laser beams are the technology used to send and received messages via communications satellites.

But any glass that is beyond the window but in the laser’s path will also return the beam. Therefore, a clock or a mirror on the ninth floor could be titled so that it would reflect laser light back down to the street, Mims said.

“But if you’re going to that trouble, it would be easier to plan an electronic bug,” he said. “Why bother with a laser?”

Microwaves, which can penetrate concret, could be employed instead. But Mims said using them is still more complex.

Mims spent three years on a still secret laser project at an Air Force center in New Mexico and has been an adviser to law enforcement and intelligence agencies.

In 1976, the National Enquirer hired him to build a device with which the tabloid, as it turned out, wanted to spy on the late Howard Hughes. The paper never actually used it, Mims said.