I don't believe so, the UV light is just directly coloring the steam blue, and the laser green. But now that you've mentioned that - I wonder how a strongly fluorescent material would look in steam and/or smoke. I'm going to take some uranium glass and hit it with strong UV in steam/smoke and see how that looks. This picture is of some of the glass in my collection under UV light.

@Observer-Effect If there is no fluorescence, where and how is the conversion to visible light taking place?

@Coffeo ? The light in the steam is visible as soon as it leaves the laser diode, and UV diodes. That's just reflection we are seeing. In the Uranium glass hit by UV, now that's florescence.

@Observer-Effect The uranium glass artifacts are very striking. But aside from the uranium glass, what else is making the UV light visible? If it isn't fluorescence, then it would have to be the camera. So, when you are just observing this phenomenon (not photographing it), can you see any light from the UV diode when it hits the steam? What happens if you replace the steam with a piece of white card?

@Coffeo Whiteboard sitting on top of my handheld laser/uv dumping shelf. Being illuminated by cheap UV penlight I use for uranium prospecting. Thinking as I type here . . . these low end LED's are known for being "leaky" - and not real clean UV-A, B or C. So even with all my options, none are for precision testing to be sure.

@Observer-Effect Yes, they are definitely emitting visible light.

@Coffeo I don't need really calibrated lights, I just use them for prospecting, art, and showing the glass in my collection.