The Cutting Edge: Computing / Technology / Innovation : PLOWSHARES : Lockheed Focuses on New ‘Liquid Lenses’

Look inside an expensive camera lens and you’ll typically find glass--elaborately ground and coated glass that enables the photographer to shoot in wide angles, at close range or in poor light, depending on the type of lens used.

But Lockheed Corp. hopes to produce better, cheaper lenses by using a different medium: liquid.

Lockheed’s optics researchers in Palo Alto, led by senior designer Robert Sigler, have invented “liquid lenses” that they say can dramatically reduce the cost of powerful camera lenses, telescopes and binoculars while enhancing the devices’ capabilities.

For instance, Lockheed says it can produce a 300mm telephoto camera lens using materials--including liquids and glass--that cost $152, compared to the $1,100 for conventional glass elements and other materials needed to make the same lens.

The liquid lens technology is derived from research Sigler’s team conducted on night-vision rifle scopes for the military. Lockheed has already licensed the technology to several camera and telescope manufacturers--it won’t identify them yet--and the first commercial telescope using liquid lenses should reach the market by year’s end, Sigler said.

When light passes through a basic high-powered lens, the light’s colors are spread apart, much like in a prism, in what is called chromatic aberration. To correct the aberration, obtain a sharp image and achieve the desired effect (wide angle, telephoto, etc.), the lens makers cement multiple lens elements together or mount them at carefully calculated positions inside the lens chamber.

They often take one other step to correct for the color dispersion: They use specialized lens elements known as apochromats, which are made from glass or crystal. But apochromats are expensive, difficult to handle and unavailable in large sizes, Sigler said.

Liquids don’t have those drawbacks, and Sigler’s team developed ways to replace the apochromatic elements with sealed liquids. Lockheed says the liquid design allows for a lens with fewer components and reduces the need for elaborately precise finishes and exotic coatings on the lens elements that remain--all of which lowers the cost.

Don’t worry: The liquids don’t slosh around inside the lens. A large lens would require no more than a cubic centimeter of liquid.

And what liquid does Sigler use? He won’t say, citing proprietary concerns. But he allowed that it’s clear like water but much thicker, a bit like corn syrup.

“Let’s just say I wouldn’t drink it,” Sigler said.