What lasers they use?

[masukaa]

Hi everybody,

I stumble upon this image (below) and I was wondering if any of you can tell me what lasers they were using. I want to do a similar project and I would love to know how they did it.

thanks in advance,
Joan

 

[Cyparagon]

Red diode lasers embedded in the floor (and/or ceiling and walls) with lots of fog.

 

[masukaa]

thanks for you reply,

would something like this make the job? laser diode



what wavelenght and output voltage is needed for the laser to be visible and be safe for the public.

 

[paul1598419]

You won't get both as only a 5 mW or less laser is considered eye safe because your blink reflex of about 0.25 seconds should keep the laser from doing permanent damage. To have a visible beam you will need plenty of fog. The 635nm laser you listed is 30 mW, so it won't be eye safe. It also won't be that visible either. Because 635nm is more visible than, say 650nm or 660nm, it should be brighter than the longer wavelength reds. But, even 30 mW of 635nm red is not very visible when you are trying to make the beam seen by all. Still, to have many 5 mW lasers in a public area is asking for trouble because that is many more opportunities to cause retinal damage before a person's blink reflex can save them from a direct strike.

 

[Cyparagon]

5mw of red is enough to be visible in the dark with fog. The lasers themselves for a project like this would be a mere few dollars. It's the huge task of mounting and wiring that has be believing this won't get out of the query phase for you.