Thin films might not come up in conversation every day, but they are all around us. Take the metallic plastic films of chip bags, for example, or the anti-reflective coatings on eyeglasses. Even the coatings on pills that make them easier to swallow are thin films. Depositing extremely thin layers of materials in a consistent and uniform way is also crucial to the production of semiconductors, which are the foundation of modern electronics. Not all materials can be easily deposited in such thin layers, such as materials with very high melting points. Now, Caltech researchers led by Austin Minnich, professor of mechanical engineering and applied physics, and deputy chair of the Division of Engineering and Applied Science, have demonstrated a laser-based method for generating thin films of materials, such as niobium. The work could directly impact superconducting electronics used in quantum computers. The team recently described the work in a paper in the journal Applied Physics Letters. A common route to producing thin films is to heat the source material up to a high enough temperature that it produces vapor, which then condenses on the growth surface to produce a thin film. But materials that contain certain elements that scientists refer to as "ultra-refractory" will only melt above a scorching 3,000 Kelvin (2726.85°C). "If you think of your coffee cup with vapor coming off, it's the same idea except, let's say, you're doing it with tungsten. Now your coffee would be at something like 3,600 Kelvin," Minnich says. "What kind of cup is strong enough to withstand 3,600 Kelvin?" The answer is there isn't one. That is why it has been extremely challenging to create thin films of such ultra-refractory materials through the typical thermal evaporation route. But thanks to developments in laser technology for metal welding and cutting, a