NextGen Lasers?

[Board of Command]

Green light? Why not blue light or is that a little too close to UV for comfort?

[KitKat]

Well, blue light is quite possible although you'd have to use different crystals to produce it. The problem with blue light is actually with our eyes. We see green light the best, because it's right in the middle of our visible range. Blue light is rather near the edge. For a blue laser and a green laser of the same power and intensity, we will percieve the green one to be 3 times brighter (I think 3, but it might be as high as 10....I can't remember the actual value, so don't quote me on this). So to have an equivalently 'bright' laser, you need to use three times the power. This may be one reason why they don't offer blue lasers on their site.

Probably the biggest reason though is cost. The crystals you need to create blue light are super expensive. Check out this site which gives an estimate for blue laser pointers at $2000 minimum cost.

[ChaosK]

green because green is in the middle of our eye's visible color spectrum, where as blue is close to the end.

but now i ask, why red? though red is a big part of the color spectrum, its still at the edge, so why make red?

[KitKat]

That's a good question with a relatively simple answer. Yes, red is on the other end of the spectrum, but you can still see red better than blue. Also, red lasers happen to be extremely cheap and easy to make. That's why you can get red laser pointers at the dollar store these days. Remember all the crystals we had to deal with in the green laser? You can actually produce visible red light directly from a diode, so you can bypass all of those other steps. These lasers are made to be quite low power, usually only a few milliwatts so that anyone can use them and they can be sold anywhere. This has led to red lasers being extremely cheap and available.