NASA engineers are experimenting with a femtosecond laser which they say can weld glass to copper, glass to glass, and drill hair-sized pinholes in different materials.
According to the team at NASA’s Goddard Space Flight Center, the new ultrafast laser could help revolutionize the way NASA technicians manufacture and assemble instrument components made of dissimilar materials.
Led by optical physicist Robert Lafon, the researchers are currently expanding their research into more exotic glass such as sapphire and Zerodur – and metals such as titanium, Invar, Kovar, and aluminum, which are commonly used in spaceflight instruments.
The goal is to weld larger pieces of these materials and show that the laser technology is effective at adhering windows onto laser housings and optics to metal mounts, among other applications.
With support from the Space Technology Mission Directorate’s Center Innovation Fund program, the group is also exploring the technology’s use in fabricating and packaging photonic integrated circuits.
These circuits are an emerging technology that could benefit everything from communications and data centers to optical sensors.
Though they are similar to electronic integrated circuits, photonic integrated circuits are fabricated on a mixture of materials, including silica and silicon, and use visible or infrared light, instead of electrons, to transfer information.
By virtue of its short pulses – measured at one quadrillionth of a second – an ultrafast laser interacts with materials in a unique way, says Lafon.
The laser energy doesn’t melt the targeted material and it vaporizes it without heating the surrounding matter.
As a result, technicians can precisely target the laser and bond dissimilar materials that otherwise couldn’t be attached without epoxies.
Another important application is in the area of micromachining, opines Lafon. “The ability to remove small volumes of material without damaging the surrounding matter allows us to machine microscopic features.”
Microscopic features include everything from drilled, hair-sized pinholes in metals – an application the team already demonstrated – to etching microscopic channels or waveguides through which light could travel in photonic integrated circuits and laser transmitters.
The same waveguides could also allow liquids to flow through microfluidic devices and chips needed for chemical analyses and instrument cooling.
Image, content: W. Hrybyk/Lori Keesey-NASA’s Goddard Space Flight Center