A Devil’s Tower-like monument rises above a sea of bubbles. It’s just another day in the life of a nanolaser researcher.
The tower is a microscopic laser in the process of being built - here, it’s shown after it was carved out of a flat sheet of semiconductor, and coated with glass. Next, it’ll be coated with metal. The semiconductor is the part that actually does the chain-reaction light amplifying, and the glass and metal are there to help keep the amplified light confined to the semiconductor, where it can continue to get more and more amplified. A little bit of this light constantly escapes - this is the actual laser emission. What makes it laser light, as opposed to regular light, is that the photons of laser light are all identical copies of each other. They’re all the exact same color, and the waves are all in step with each other. In the case of the laser above, the laser light will emit through the bottom, like a little nanolaser rocket.*
*nanolaser will not actually fly.