Rogue One introduced the idea of Kyber Crystals in the Star Wars movie Canon.

In the 1977 movie A New Hope - we see Obi-Wan Kenobi and Darth Vader battle with lightsabers and the blades repel with a 'clashing' sound.

A New Hope lightsaber duel

Also in the 1977 movie A New Hope, they introduce the Death Star. According to Rogue One the laser in this was also built using Kyber Crystals. We see in this the laser beams coming together to combine into one large beam:

Death Star firing

My question is: Why do lasers from Kyber crystals in light-sabers repel noisily but lasers from Kyber crystals in the Death Star combine?

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    They’re not really the same thing; they just use similar technology. In particular, at least the first one is not a laser.
    – Adamant
    Jan 13, 2017 at 10:15
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    They're also not lasers.
    – Paul
    Jan 13, 2017 at 11:42
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    Keep in mind it took a whole bunch of geniuses a long time to figure out how to build the superlaser. I don't know whether "making the kyber crystals work together rather than conflicting" is canonically one of the problems they had trouble solving, but it might have been. Jan 13, 2017 at 23:13

3 Answers 3


Because lightsabers are not made of lasers

According to Wookieepedia, which cites Star Wars Rebels: Visual Guide, the lightsaber blades are made from plasma. According to some pre-Disney explanations the lightsaber blades are made of plasma which is contained via an electromagnetic field; I assume the blades repel each other because of this field.

As for the Death Star, its main weapon is a superlaser - a big laser beam made of smaller laser beams. Combining laser beams is a real thing, though in the real world it requires a lens.

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    Well...the Death Star obviously must be programmed in C++, so the lens is simply declared virtual - and there you go..! :-) Feb 26, 2018 at 3:52
  • @BobJarvis-ReinstateMonica Or, on a more serious note, that big dish front-and-centre (around which the smaller less-super lasers are arranged) could be generating an electromagnetic field at its focal point, which acts as a (virtual) lens and/or "containment bottle" / capacitor - hence why they combine and pause before firing! Mar 6, 2020 at 16:39

Lightsabers and "Lasers" (AKA blasters) in Star Wars both work on the principles of trapping plasma in a powerful electromagnetic field. No doubt Kyber crystals are used to somehow generate the exceedingly powerful electromagnetic fields. The field tells the plasma where to go. A lightsaber is designed to trap the plasma in a long narrow blade, and when two lightsabers strike each other, their electromagnetic fields repel each other. This is like how two bar magnets will repel each other if you try to bring both their North (or South) poles together. The Death Star works on the same principle but it is engineered so that the electromagnetic field generated by the Kyber crystals takes many small beams of plasma, combines them into one larger beam, and then shoots that beam out to blow up planets.


Kyber crystals in lightsabers are made from blown up Stars the kyber crystals in the Death Star were artificially made to do what they need to do so then they can combine

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    Can you back up this bold statement with any actual evidence?
    – Valorum
    Dec 20, 2019 at 23:18
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    Hi, welcome to SF&F. Can you please provide references or quotes to back this up? IIRC, Rogue One showed the Empire raiding existing stores of Kyber crystals rather than manufacturing them.
    – DavidW
    Dec 20, 2019 at 23:18
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    @DavidW The Empire attempted to synthesize kyber crystals IIRC but their efforts were generally failures, so the Empire went to work seizing and strip-mining planets for legit crystals. That's if I'm remembering Catalyst: A Rogue One Novel correctly. Dec 21, 2019 at 0:29

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