system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Can there be invisible lightsabers?

Most military lasers are actually invisible due to the fact that it is mostly ultraviolet light. Knowing that lightsabers can come in different wavelengths (red to violet) depending on the crystal used, are there crystals that create lightsabers in invisible wavelengths?
gpt
The "blade" of a lightsaber is made up of a few different components, and the interaction and combination of those components is what gives a blade a color. While this color is dependent on the crystal, it's not the only factor. A lightsaber blade is an ionized plasma contained in a forcefield. The fields interaction with the local atmosphere and the temperature and properties of the material contained by it will affect the color. While it should be possible to push the wavelength of radiation emissions outside of the common visible frequencies, it would be hard to eliminate anything in those ranges, as most gasses in atmospheres electroluminesce (sp?) on their own. Not only would you need an invisible forcefield, you would need a specific gas (which means you would have to ignite the lightsaber in a controlled atmosphere) inside the field as well.