digital breakthrough

Lightsabers and Quantum Dots

The recent surge of interest in my post about Kyber Cristals produced an interesting side effect.

As I scoured the Internet looking for nice pics of visible light spectrum, I encountered not a few articles on the most recent breakthrough in digital display production: Quantum Dots. Or, more precisely Quantum Dot LEDs.

What’s a “quantum dot”? In a nutshell, it is a semiconductor nanocrystal, whose size is so small it’s just several molecules wide.

That, of itself, is not interesting. What’s interesting is that: If you give a quantum dot some energy to excitate its electrons, when its electrons return to the normal state, it would emit light whose wavelength correlates to the size of the quantum dot.

Large quantum dot = longer wavelength = Red light.

Small quantum dot = shorter wavelength = Blue/Violet light.

And the wavelength can be precisely tuned. Make it even smaller and it emits ultraviolet. Make it even larger and it emits infrared. Or make in somewhere in between and it can emit cyan, green, yellow, or any other visible light frequency.


The color of a lightsaber’s blade depends on how big (or small) the quantum dots formed in the Kyber Crystal were. And how “uniform” / “homogenized”.

Larger dots: Mostly red ==> Red blades of the Sith, who “forced” the crystal to work, inadvertently combining smaller dots into bigger ones.

Smaller dots: Mostly blue ==> finely tuned with the Force, letting the Force ‘settle’ the crystal gently and naturally, resulting in nice, small nanocrystals.

What about Ahsoka’s white lightsaber?

Well, for some reasons, the dots formed were of various sizes. KInda evenly distributed, perhaps.

I surmise that it was a soup of large-, medium-, and small-sized dots. The large dots were formed by the previous owner (”Sixth Brother”), and the medium- and small-sized dots were created by Ahsoka, either newly, or as remnants of large dots broken into smaller dots.