|MadSci Network: Engineering|
Hello Jake, That's a very interesting question! Let's use the visible "additive" colors as an example - red, green, and blue. Each one has a different wavelength, but varying the amounts shown upon a surface of any two or more of them can produce any other color. Just as three pebbles thrown into a pond, each representing one of those colors, the wavefronts will at some point, meet and create another, very different ripple. This new ripple will have a different wavelength than any of the individual ripples; depending on how often (or the frequency at which) the individual ripples meet each other. So it is with light waves which intersect. At the point of intersection, the individual light rays will re-inforce, and then negate each other causing an entirely new frequency (wavelength) to be produced. Laser beams are no different - except that they are a "pure" form of emmission, producing only one fundamental frequency or wavelength. Therefore, it certainly is possible to produce visible light from two or more invisible laser beams. What the eye will see is the new frequency produced by the reinforcement and negation of the intersecting beams. A simple experiment with sound will prove this theory. If you send a high frequency, somewhere above the range of human hearing (like 30KHz), to one loudspeaker and another high frequency to second loadspeaker, by varying the frequency of one of them, a third audible tone will be produced, provided the two frequencies "beat" together within the audible range. Try it! Without going through the math, you should be able to take one Infrared laser (around 1000nm wavelength) and a Ultraviolet laser (<400nm) and produce something in the visible range. Try it! - BUT MAKE SURE YOU USE PROTECTIVE EYEWARE! Remember, what you can't see CAN hurt you! If you need any more help, you can contact me directly at: KarlKolbus@ameritech.net. Your not-so-mad scientist, Karl
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