Ultrapure Yellow Laser from Diamond express
The laser based on diamond converts almost half of the pump energy into bright yellow light — an efficiency of 47.7%, a record for such devices. But the main advantage is not the power, but the exceptional purity of the color: the beam is so monochromatic that it can be compared to a musical instrument playing just one note without the slightest wavering.
The light frequency was stabilized using absorption lines of sodium vapor — the very element that gives the familiar orange glow to street lamps. Thanks to this, the instability is squeezed down to 6 hertz: if the laser's frequency were a clock, it would lose less than a second in a million years.
This stability opens the door to telescopes capable of scrutinizing the atmospheres of distant exoplanets, and to quantum computers where every photon must arrive exactly on time.
That very same yellow light from street lamps is pushed here to the limit of precision — its frequency stays constant to within billionths.