Ultrafast Laser Welds Glass to Metal

An ultrafast laser under development at NASA (nasa.gov) is able to weld dissimilar materials, including glass to metal.

A team of optical physicists at the NASA Goddard Space Flight Center is experimenting with a femtosecond laser and has already shown that it can effectively weld glass to copper and glass to glass.

By virtue of its short pulses—measured at one quadrillionth of a second—an ultrafast laser interacts with materials in a unique way, NASA optical physicist Robert Lafon says. The laser energy doesn’t melt the targeted material. It vaporizes it without heating the surrounding matter. The vapors of dissimilar materials mix, then cool, creating a weld. Technicians can precisely target the laser to bond dissimilar materials.

It hasn’t been possible to bond glass to metal directly before now, Lafon says. “You have to use epoxy.” Because of things like outgassing and potential contamination, this isn’t good for NASA-type components. “We want to get rid of epoxies.”

The group is expanding its research into more exotic glass, such as sapphire and Zerodur, and metals, such as titanium, Invar, Kovar, and aluminum—materials often used in spaceflight instruments. The goal is to weld larger pieces of these materials and show that the laser technology is effective at such applications as adhering optics to metal mounts and windows onto housings.

While this may be a long way from welding windshields in place, it has to start somewhere.