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Posted: Sun Jan 13, 2008 4:26 am
by jon_89
so what is wavelength?

Posted: Sun Jan 13, 2008 4:37 am
by Novacastrian
jon_89 wrote:so what is wavelength?
Wiki should be able to tell you that :)

Edit: Well i'll be, wiki has no such information.
Wavelength refers to the size or length between two "waves" or "pulses". Usually measured with time. Think of the ocean, how long before the next wave hits, except with electronics this period of time is expressed by milliseconds.

Posted: Sun Jan 13, 2008 4:38 am
by Eddbot
Image

wavelength is the distance between the troughs(bottom), or crests(top) of a wave, as the wave moves forward, it goes up and down in the same exact pattern (unless it gets reflected or refracted or...i forgot the other one)

the nm has to do with the amplitude in the picture above, a laser wave is measured from the crest to the trough in nanometers

the shorter the wavelength and smaller the amplitude, the stronger/brighter/burnier the laser will be *huff* i'm done lecturing, even though i know someone is gonna add/correct something i messed up on

edit: do i just take too long to type stuff, i always get beat to the post

Posted: Sun Jan 13, 2008 12:38 pm
by jimmy101
jackssmirkingrevenge wrote:As far as I can tell, MW is milliwatts, a measure of power, while NM refers to nanometres, a measure of the wavelength perhaps?
Yep,
MW = milliwatts (the power in the light beam). A MW is not much energy, even when concentrated on a small area.
NM=nanometers=wave length of light produced="color" of the light produced
Wavelengths:
Red (635 nm, actually may appear slightly orange-red) through deep Red (670 nm) and beyond,
IR (invisible) (780 nm, 800 nm, 900 nm, 1,550 nm, etc.) up to several um.
Near-UV, violet, and blue laser diodes are available from around 380 nm to 450 nm but are still very expensive.
Green laser diodes have been produced in various research labs but until recently, only operated at liquid nitrogen temperatures, had very limited lifespans (~100 hours or worse), or both.
http://www.repairfaq.org/sam/laserfaq.htm

Other common specs of a laser;

Its diversion (sometimes miss labelled as dispersion). The diversion is basically how much the dot spreads out as a function of distance. Diversion is usually in the range of a milliradian or so.

Dot size, which is typically in the range of 0.5~2mm diameter.

Posted: Sun Jan 13, 2008 12:44 pm
by jimmy101
Eddbot wrote:the nm has to do with the amplitude in the picture above, a laser wave is measured from the crest to the trough in nanometers

the shorter the wavelength and smaller the amplitude, the stronger/brighter/burnier the laser will be *huff* i'm done lecturing, even though i know someone is gonna add/correct something i messed up on
Nope. "nm" is the wavelength ("color"), not the amplitude (brightness).

There is no obvious relationship between wavelength and amplitude. You can have a small wavelength and a large or small ampliltude. Or a large wavelength and a large or small amplitude.

Posted: Sun Jan 13, 2008 1:28 pm
by jon_89
so if i was to buy a laser module which one would be the "hottest"? a 650nm 10mw, 780nm 80mw, or a 980nm 35mw.

Posted: Sun Jan 13, 2008 1:40 pm
by dewey-1
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Posted: Sun Jan 13, 2008 1:47 pm
by jon_89
to burn a hole in a piece of half inch steel plate. :twisted: jk. maybe burn a hole in paper from 2 feet away or is that asking for to much.

Posted: Sun Jan 13, 2008 2:23 pm
by dewey-1
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Posted: Sun Jan 13, 2008 3:50 pm
by iPaintball
I have made two burning laser pointers using the DVD burner method. If you are going to attempt this, dont EVER point the diode towards your eyes. A diode as powerful as a DVD burner diode is likely to burn/damge your eyes instantly, and they can also cause blindess very quickly. Don't stare at the impact point of the beam either. The IR radiation reflected off of the object you are burning can also cause eye damage. I would read up on laser safety before constructing your laser. If you need some more detailed instructions on how to do this, I posted a how-to on theopia here.

Posted: Sun Jan 13, 2008 3:57 pm
by jon_89
well i think for the sake of simplicity i will make the one on page 1.

Posted: Sun Jan 13, 2008 4:15 pm
by spudy buddy
could u use this as a laser sight on a spud gun?

Posted: Sun Jan 13, 2008 4:18 pm
by MrCrowley
No point, spudguns aren't accurate enough anyway.

I tried to calibrate a proper scope to my paintball gun, no point with any object that is spherical in a smoothbore barrel.

Posted: Sun Jan 13, 2008 4:47 pm
by jon_89
Now for the ultimate question. Is a 650nm 10mw laser module from Aixiz worth $12? Is this all I need plus batteries? Or should I go for something different?

Posted: Sun Jan 13, 2008 5:10 pm
by iPaintball
no, you need the burner diode. The module you are referring to will just make a bright red dot.