TOTALLY new to lasers PLEASE HELP

Welcome rickrush; Chances are actually any lasers you used in your physics class (probably) were around 0.5 mW HeNe 632.8nm. That's 1/2 a milliwatt.

I've had some friends who got curious about my lasers get somewhat crestfallen when they learn that "mw" is milli not mega. However, folks have to remember that when comparing to a 60 watt lightbulb, that energy is A) mostly converted to heat and B) completely non-coherent, going every which way. 60mW of a concentrated beam will burn things. Generally only dark items - but it'll smoke 'em nonetheless. That's for later, though.

$10 for the DX 5mW laser *is* a good start and at 532nm green, its relative brightness will likely surprise you. Just be careful! The DX lasers tend to at times get overambitious - I have one that was purchased as 5mW and jumps up to 80mW sometimes. Remember all eye safety guidelines as if it wasn't 5mW! (Don't reflect it off of shiny surfaces into your face!)

In any case, a premature congrats on your first laser, and, here's suspecting that it will not be your last. I'm also in some of the photography forums where we talk about our DSLR cameras and the affliction known as "LBA" - "Lens Buying Addiction." Unfortunately for me I have *TWO* diagnoses of LBA; the second one being "Laser Buying Addiction".

Take it slow, there are a lot of good resources here, and welcome to it.

Thanks! Yeah we only used one laser really, it was just a lab style red one, not sure of the power. I was just amazed at the wavelengths and frequencies of visible and non visible light. Oh yeah I'm definitely getting the green 5mW laser i was talking about, really excited One thing I don't get though. Why are yellow lasers like 2734569283756 dollars for like a 2mW one?

Yellow DPSS is a new technology, Green USED to cost that much.

Patience Padawan, they will come down some day.

DPSS= Diode Pumped Solid State

Blue (473nm) used to cost that much too, and it's coming down even faster. Yellow is a more complex process than green or blue (green and blue are frequency doubling; yellow is frequency doubling and then summing) but still, powers are going up and prices are coming down. Slower than we'd like, but it is happening.

mW = milliwatts, MW = megawatts, Mw doesn't really mean anything...lol

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In chemistry mean molecular weight

Good! I REALLY want yellow and orange lasers but I'm pretty poor.

Another thing I was thinking about, is what the different wavelengths do. It seems to me that each wavelength has strengths and weaknesses, is this right, or just crap?

There isn't much difference between wavelength except price, color, and the smaller wavelengths are slightly better at cutting things(i.e.405nm is better than 650nm)

Ohhh alright

Yah -- OK

HMike

rickrush said:

Good! I REALLY want yellow and orange lasers but I'm pretty poor.

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You can get a 635nm laser for about $20. The second one from the left in my avatar is a 635nm laser, which are a very orangish red color. A laser with a 635nm diode will have a tolerance of +/- 5nm, which means a good one can be as low as 630nm, and as high 640nm. In other words, they are a crap shoot. Some will look orangish red (but obviously still red) and some look very orange (to the point that random people will say it's orange, not red). I suspect mine is closer to 630nm. I would love to have it tested spectroscopically.

As for yellow, well, it's just the best!

Hey, I bought the blue laser from this post ( http://laserpointerforums.com/f38/inexpensive-blu-ray-laser-pens-worth-look-46487.html ) and I have had it for a week or so and it suddenly got really dim. I thought it was the batteries so i got some new ones and threw them in but its still REALLY dull and I don't know why. Anyone know why this might happen or how to fix it?

I've had one of these "go dim". For a while, it even went 'pulsed'.

With these ones i've found a few issues.

1: The "screw-together" junction sometimes doesn't conduct very well. There seems to be a silver paint over brass on the threads. Sanding the threads (lightly!) to make a better connection helped one of my 'dim' blu-ray pens.

2: Same goes for the little brass spring in the head part. Used fine grit sand paper on that too, to get rid of any oxidization.

... To see if this is the problem before doing it, try unscrewing it slightly while the button is depressed and see if you get your bright beam back. In my case, if I unscrewed it a few turns and wiggled it, the beam would get bright again, but if I screwed it back together completely, it'd go dim. Until I did #1 and #2 above. Now it works fine.

Let me know how that goes... The drivers and diodes in these usually don't just go dim - they either work or they don't...

WOW thank you SO much aryntha! i just adjusted the screw threads a bit and i can see the beam and the dot is blinding again thanks man i really appreciate it

Not a problem. To make it permanent, do make sure to sand them slightly (and i do mean slightly! Just barely enough to expose a bit of the brass under the metallic paint!) with fine grit paper, and then maybe put some DeOxit on there.

Either way, that 'screw together joint' is probably THE weakest link with these "ebaysers".

Another thing i've found, is that they tend to have at least a slow idle drain. Meaning if you leave batteries in them, even if you leave the laser in a drawer, it'll drain the batteries very slowly. So I usually don't leave any AAA's in mine.

Glad to hear it worked, and at least now if it happens again you know where the problem likely is.