A new way to create diamond-structured crystals, discovered by Army researchers, creates a method for scientists to build more powerful lasers, which are found in key targeting and missile defense systems.
The standard way of making the necessary crystal structures for lasers uses either string-like or “close-packed cubic colloidal crystals.”
Those forms didn’t provide the necessary foundation for use with certain wavelengths of light.
The new diamond lattice structure that’s been created could play a major role in more efficient, smaller, lightweight laser systems, light-based quantum computing, atomic clocks and gyroscopes — all key to precision navigation and timing, the backbone of complex modern targeting systems.
The “photonic technique” was conducted by researchers at multiple universities, funded through Army research into laser technology.
“There’s been a great desire among engineers to make a diamond structure,” said David Pine, professor of chemical and biomolecular engineering at New York University, one of the co-authors of a recently published article in the journal Nature.
“Most researchers had given up on it, to tell you the truth — we may be the only group in the world who is still working on this. I think the publication of the paper will come as something of a surprise to the community.”
Evan Runnerstrom, the program manager for the Army Research Office, part of the Combat Capabilities Development Command, spoke with Army Times about the new development.
“We know that particular structures like the diamond lattice are really attractive to being able to control light in 3D,” he said. “If you trap light or design the structure in certain ways, you can direct the light in certain ways.”
For a practical example, he said that the laser from this kind of structure would be more sensitive to detecting an incoming projectile and use less battery power in a field scenario.
And while the laboratory research isn’t going to hit a system immediately, Runnerstrom estimated that the process will show whether it is scalable and worth pursuing over the next three to five years.
The colloidal crystals consist of microscopic spheres that can be arranged into a variety of shapes, depending on how they link up.
Each attaches to another by way of DNA strands glued to surfaces of the colloids like a “molecular Velcro.”
The colloids collide in a liquid bath, the DNA snags and they link. The structures can then be programmed into complex structures.
Because they do this spontaneously, scientists can likely complete the process at a much higher scale. Past attempts have approached the problem in a top-down way, Runnerstrom said.
That requires separately patterning every layer, which is very labor-intensive and not conducive to creating a more complex, open structure such as the diamond lattice, he said.
Runnerstrom said the science behind this has vexed many researchers in the past.
“Many people have tried and not been successful,” he said. “What made this successful was Pine approached ARO with a compelling idea. It is a high risk but compelling idea and the potential rewards are high enough.”