For example, if I take 2 laser pointers and arrange them in such a way that their beams cross each other (forming a kind of "x") will the resultant colour at the point at which they intersect be of a very high intensity? E.g. take 2 laser pointers, of which one produces blue light and another red, but the beams of light are barely visible. Where the two beams intersect, will the brown colour be of higher intensity? (If you didn't know: blue+red=brown.)

Laser pointers use diodes (that's why I used the tag).

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    $\begingroup$ When I say "intensity" I also happen to be reffering to brightness $\endgroup$ – Skylar Aug 23 '16 at 9:20

First, when one mixes color then blue+red does not make brown. Mixing color is different from mixing pigments.

When two laser beams from two different laser pointers cross at the same point, the intensity at that point would be double the intensity of the individual laser pointers. Intensity is defined as the power per unit area and power is the energy per unit of time. The light from each laser pointer has a certain power. One can find the (average) intensity of the light spot that it produces by dividing the power of the laser pointer by the size (area) of the spot. So when two laser pointers, with the same power, producing the same sized spot, shines on the same point, the intensity at that point would be double the intensity from one laser pointer. This would be the case, irrespective of the color of the laser light.


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