Why there are no strong Red lasers?

[Crashpc]

I´m just looking for some cheap (i.e. 200-400$) strong laser for burning. I like Rayfoss because of its price, But I could not find any red stronger than 200mW for this price, while 200mWs are for almost free literally (against othe coloured lasers). Why is that?

 

[Pontiacg5]

Its because after 200mW the diode is multimode and has a very horrible beam. The divergence is really bad and the beam and dot are actually square instead of round. Its really no good for pointing because of the divergence, and its no good for burning because its hard to focus.

 

[daguin]

I´m just looking for some cheap (i.e. 200-400$) strong laser for burning. I like Rayfoss because of its price, But I could not find any red stronger than 200mW for this price, while 200mWs are for almost free literally (against othe coloured lasers). Why is that?

Higher powered red diodes are usually multi-mode and so require more complex optics to get them to make a nice beam/spot.

You can build (or have built) a red laser that will do >300mW with the Jayrob 650-G-1 lens.

If you need to go higher than that, you will have to go more expensive or go to a lab-style laser.

Peace,
dave

 

[Crashpc]

Thank you. I go with green which can be more powerfull and visible for better price in handheld laser I guess...

 

[Grix]

If you just want burning, you should look into a blu-ray laser. You can have a 500-600mW one for about 300-400$. Now THAT's a lot of burning power.

 

[Crashpc]

Thanks, I´ll have a look for prices. I really don´t need some badass device able to kill me even before I turn it on. The same way as MOT transformator from microwave etc. I just need to light a match quite fast, and other small things(thats something between 200-350mW I quess). There will come up the power input issue for highest powered lasers. I don´t want to carry car battery like power supply for it, and charge it every two minutes of device work…
So if there will be some blu-ray 350mW one, I´ll be deciding between it and green one...

// and I want it for its strong beam too, to make nice photos with it

 

[Pontiacg5]

100-200mW should light a match if the beam is a good size. Green is quicker to burn stuff because it usually doesn't have to be focused. With a bluray laser you will probably have to focus it to burn anything.

 

[daguin]

100-200mW should light a match if the beam is a good size. Green is quicker to burn stuff because it usually doesn't have to be focused. With a bluray laser you will probably have to focus it to burn anything.

^^^^^^^^^^^^^^^
Shows a basic misunderstanding of lasers and optics.

Peace,
dave

 

[Pontiacg5]

And how is that? By good size I didn't mean big, but normal size for green dpss lasers. Bluray diodes and red diodes usually have a big beam that you would have to focus down to a small point. Therefore if you were to have two lasers, one green and one bluray, both focused to infinity, the green one would light the match faster because the bluray would have to be adjusted first.

 

[chipdouglas]

I just need to light a match quite fast.

:wtf::crackup:

 

[daguin]

And how is that? By good size I didn't mean big, but normal size for green dpss lasers. Bluray diodes and red diodes usually have a big beam that you would have to focus down to a small point. Therefore if you were to have two lasers, one green and one bluray, both focused to infinity, the green one would light the match faster because the bluray would have to be adjusted first.

First off, green lasers are focused. They also have a "wide" beam before focusing optics. It is just that most of them are already focused to infinity. MANY of the newer green lasers are now coming with focusable optics because being able to focus them makes them MUCH better burners.

Being focused to infinity does NOT make the laser a better burner. It makes the laser equally bad at all distances. It would be MUCH better if it was focused.

If both the green laser and the violet or red laser were focused to infinity, the differences in burning ability would be affected MUCH more by the colors of the thing being burned than they would be by the "width " of the beam.

Focusing a laser with an exposed lens nut (like most of our red and violet lasers are) takes about one second. A focused beam of the same power will ALWAYS burn the same object faster than a beam focused to infinity (given the above mentioned color differences).

Peace,
dave

 

[BShanahan14rulz]

Remember that Sharp commercial? Or was it sony?

It's all in the "meers". Well, the optics, even.

What PontiacG5 is trying to say is that experience shows that most common green lasers are smaller at the aperture. Not sure why, have to play with more lasers, but I'm willing to bet that a beam expanding lens set would be used in higher-end modules, to cut down divergence, before collimating.

What Daguin is trying to say, I think, is that not only does sheer power affect the burning equation, so does power per area.

Now, what I'm adding, something about how since beam diameter is so small divergence goes to crap. Also, Bluray, Red, IR, all diodes, all focus the same, more or less.

This post was authored over the span of a few hours. My thoughts probably don't connect too well...

 

[Pontiacg5]

What I am trying to say is that in most situations green lasers have a smaller beam diameter while focused to infinity which equates to more power per square inch which equals more burning power. A bluray or red laser with the same power also focused to infinity usually has a fat beam which would equate to less power per square inch which would make it burn less.

I have had a focusable red laser, and I have a green laser with a narrow beam. The red laser would have to be focused to do any burning then you have to refocus it to get it back to infinity which is a PITA because to get the laser focused to infinity the lens needs to be perfectly placed and its easy to overshoot that setting. My green laser will light a match just about anywhere along the beam to about 6 feet, and I never have to change anything.

Focusing lasers are a pain in the ass, I would take a nicely culminated small diameter green laser over a focusable laser any day.

And notice that in my first post, I didn't say the green would burn better I said it would burn quicker which is true.

Notice how most high quality green lasers don't come with adjustable focus (unless you ask for it from CNI) That's because there is usually no need to focus a green laser. Which IMHO makes it a better burner.

 

[chipdouglas]

Remember that Sharp commercial? Or was it sony?

It's all in the "meers". Well, the optics, even.

What PontiacG5 is trying to say is that experience shows that most common green lasers are smaller at the aperture. Not sure why, have to play with more lasers, but I'm willing to bet that a beam expanding lens set would be used in higher-end modules, to cut down divergence, before collimating.

What Daguin is trying to say, I think, is that not only does sheer power affect the burning equation, so does power per area.

Now, what I'm adding, something about how since beam diameter is so small divergence goes to crap. Also, Bluray, Red, IR, all diodes, all focus the same, more or less.

This post was authored over the span of a few hours. My thoughts probably don't connect too well...

the green is falsely smaller at the aperture. the aperture is a cap well at least on my with a drilled hole to let the beam go through. and the hole is small and reduces some haze. i don't know if i worded that correctly but i think you get what i am saying.

 

[RA_pierce]

@Pontiacg5:

The color/wavelength of the laser does not determine the diameter of the beam. The optics do.

You are correct that when focused to infinity, a typical green laser of equal power will have higher power density at aperture than a typical red or violet laser. But I don't see how focusing a laser is such a PITA, especially when doing so is as trivial as turning a ring.

Also, a laser with a large beam diameter is capable of better divergence. So your green may be better for burning up to 6 feet, but after 6 feet, the beam of the red or violet will have diverged less, and therefore be better for burning at longer distances.

the green is falsely smaller at the aperture. the aperture is a cap well at least on my with a drilled hole to let the beam go through. and the hole is small and reduces some haze. i don't know if i worded that correctly but i think you get what i am saying.

Green lasers are designed to have small beam diameter and low divergence.

A laser beam should not be "cut off" in order to obtain a smaller beam. It is a horribly inefficient way to get "good beam quality."
DPSS green lasers already are capable of almost perfect gaussian beams without an aperture that cuts off half of the beam.

The laser you are referring to must be absolute garbage if the beam is so horrible that half of it must be blocked.

 

[BShanahan14rulz]

the aperture protects the lens. the beam is way smaller than the hole in the aperture. Plus, as RA said, it's not a laser diode, it's a solid state laser, so it makes a nicer beam already.

Red is strong, just looks dimmer.

Green is much brighter, but the beam is also generally thinner when "focused to infinity"

hypothetical red and green lasers, both output the same power, both focused to infinity.
green will look brighter than red (green puts out more lumens)
green will burn stuff better than red because of its smaller diameter. Think all that power going into a smaller spot than the red.