The Cutting Edge: Computing / Technology / Innovation : Computer Research Sees the Light

For the derogatory term air head substitute gas head , and you will have a fitting description of what may become the brain of future optical computers. In a paper published recently in the British science journal Nature, a team of USC physicists describe a device that could function as a central processing unit consisting of nothing more than a thin glass cell filled with cesium gas.

Optical computers use light rather than electrical signals to process information. In principle, they can run many times faster than today’s computers because they operate at the speed of light. And for pattern recognition, they are much more adept than electronic computers because they compare patterns simultaneously rather than in one after the other.

Cesium gas is extremely sensitive to light, making it a useful element in an optical processor. Say you had an aerial photograph of a battlefield and wanted to determine how many tanks were in the photo. Projecting one laser beam containing the information from the photo and another from a picture of a tank would change the frequency of the cesium electrons wherever there was a match.

A third beam coming from behind scatters off the image, creating bright spots where there is an overlap. Because the cesium vapor responds quickly to these low-power beams of incoming light, the prototype developed by the USC team performed computations in 30 nanoseconds (30 billionths of a second). Other materials now used require several billion times as much power input and therefore can perform the calculation only 10 times per second.

Electronic Assistant: Tired of having to place a number of calls from that airport telephone booth just to be sure you’ve gotten all your e-mail messages and voice messages, then make follow-up calls while precariously balancing your Rolodex? How about asking your Wildfire Electronic Assistant for help.

The brainchild of Wildfire Communications of Lexington, Mass., the device is the first telephone-based electronic assistant that interacts with harried mobile professionals through voice commands.

Nor do you have to carry it with you. The Pentium-based computer system that runs Wildfire is installed at your office and connected to the public telephone network by a high-speed T-1 connection. A built-in database stores user and system information, and the operating system enables the software to use speech-recognition hardware.

The system recognizes each caller by name and knows exactly where to find information relating to that caller. It maintains a list of telephone numbers so the user can “voice dial” outgoing calls simply by asking for a person by name. Wildfire screens calls and routes important ones to your hotel room or car phone. And it will schedule follow-up calls--all through voice commands. But none of this comes cheap: The system will begin shipping in January at a price of $46,850.

Seeing Eyes: For photographers, the camera is an extension of the human eye. But researchers also want to photograph the inside of the living human eye with as much detail as possible as an aid to treating eye diseases. This week, scientists at the University of Rochester in New York announced that they have taken the sharpest pictures yet of the eye’s cones--the photoreceptors that allow us to detect color and see clearly during the daytime.

The Rochester scientists shined a low-power beam of yellow light from a dye laser through the pupil and onto the retina, the screen inside the eyeball that captures light signals and transmits them to the brain. The retina, which is packed with photoreceptors, reflected the light back to a special electronic camera outside the eye that is many times more sensitive than photographic film. In contrast to the 10-micron structures that the instruments your eye doctor uses can see, the team was able to see individual cones about three microns wide. Seeing these individual cones could help doctors detect or treat several types of eye disease, including age-related macular degeneration, the leading cause of blindness in the elderly.

Guiding Lights: Like lighthouses of old, modern-day beacons will eventually guide Japanese drivers through the rough waters of traffic jams. Japan’s National Police Agency has come up with a system called a Universal Traffic Management System, which it intends to deploy in traffic-clogged Tokyo in early 1996. One feature of the system, now on trial in Kanagawa Prefecture south of Tokyo, is to change the intervals between signal changes, depending on the amount of traffic. Optical sensors along main roads and at crossings would detect the speed of passing cars and beam that information via FM transmitters to control centers. Based on the information, the centers decide the frequency of signal changes.