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Lasers.... A must have for the physics minded


ScienceFreak
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Ok you guys got to get one of these!!! I just bought one, and these lasers are bad!!! you guys got to get one!!!

 

Go here and check them out: http://wickedlasers.com/index.php?promo=4433

 

This is great to do experiments with..... And study...

You can touch the sky with this thing....

Only two AAA batteries power this thing, you got to see it for your self...

 

 

If you guys do buy one use this promo code: 4433 and use the add to basket button....

 

But if you click on the link above you should already have it activated.... THIS WILL GIVE YOU 5% OFF YOUR LASER!!!

 

These thinks are bright!!! You can point out stars in the sky with it....

 

And it can burn stuff.....

 

 

If any of you get one keep me up posted on your experiments and any ideals you come up with.....

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They're expensive!

 

I've got a 5mW green laser and a collection of red ones, but nothing like 15, 35 or 300mW.

 

You are only legally allowed to own up to 5mW without a license, I think.

 

Besides this is advertising which you're not really meant to do on SFN.

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I know when I first saw this site, I was like WOW! I have to get me one of these things! and I was glad I did I first bought a 15mW and know I just bought a 75mW; I can not wait to check it out.

 

The Forum that they have on there website, also has some great people in there that are GREAT to talk with, very helpful!

 

Sorry if this looked like advertising, but I wanted to see if we could get a nice discussion going on here about lasers and neat experiments on these powerful coherent beams!

 

Like I said they have a nice Forum over on there website but I wanted see what you guys could come up with (you know different minds) :)

 

And ya I know they are a little price, but that is why I also gave you the promo code, which will help you out a little...

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I want a 50mW one! Where did you [YT] get yours from?

 

If only I had a few hundred pounds/dollars to buy a 100mW laser...

 

Swansont; Don't bully my laser! And how much did your one cost? Is it one at where you work?

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erm' date=' I have a 640nm 50mw laser here, so Im breaking the law :confused:

 

Stoopid Law then! :P[/quote']

 

That'd be a class 3R laser.

 

There's no specific laser laws in the UK, but there are general public safty and general sales saftey laws which have been argued to cover this. And the current guidelines say you shouldn't sell anything over 5mW I think.... Althouth my memory on this is a big sketchy :|

 

According to the guidelines if that was a laser in a work place you would not have to appoint a safty person for it because it's inside a certain set of wavelengths.

 

And it's not a stupid law anything over and including a 3R laser can cause damage to the eye by very short term accidental viewing....

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eBay won't sell anything over 5mW now, however there are a bunch of mod kits and people who say "once the transaction is complete I could mod it for extra $$$"... how good are these increase-power kits and even if someone else did it for you how does a 5mW laser react to being changed to 10mW???

 

3R laser? Do you mean IIIb or 3b? I've never heard of 3R. This is what I've always gone by:

http://ehs.uky.edu/radiation/laser_fs.html

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Dunno where I got this from, but I saved it in my stuff.txt file on my desktop coz it's really cool and I wanna do it some day!

I did a demo in my lab in grad school - took a boom box output' date=' modulated a laser diode (780 nm), sent the light across the

room to a photodiode, sent the output into another boom box and played the music. I thought it was one of the coolest things I'd seen. Aside from setting up the laser system (which had happened already) it only took a few minutes plus the time to wire a BNC-RCA cable.[/quote']If you had a green laser in a dark room you could actually watch your sound being transmitted across the room encoded in the laser beam, how coool!?!

 

From here:

http://www.geocities.com/Tokyo/Harbor/2308/

When giving presentations, you can use your laser pointer to point out certain things on the overhead projector. Instead of getting in everyone's way by normally using your hand or a pen, stand back, and use your laser pointer and let the red dot do all the guiding.

If you work in construction or your an architect, use the laser to point out certain things of your project that are normally out of reach.

If you are a weather man, i've seen people use them on TV to point out things on the map when they tell us the weather.

If you are a doctor, use laser pointer when showing x-rays print outs.

If you are a teacher, you can use them to point things out on the black board or around the class room.

For law enforcement, we use them to point out things at crime sceens where we normally can't go. Or use them to show for example: Where the criminal ran or the window the criminal escaped from...etc.

 

I dunno what really useful things the average person can do with one, but they're soo cool... love lasers!

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  • 3 weeks later...
eBay won't sell anything over 5mW now' date=' however there are a bunch of mod kits and people who say "once the transaction is complete I could mod it for extra $$$"... how good are these increase-power kits and even if someone else did it for you how does a 5mW laser react to being changed to 10mW???

 

3R laser? Do you mean IIIb or 3b? I've never heard of 3R. This is what I've always gone by:

http://ehs.uky.edu/radiation/laser_fs.html

 

well that`s Odd because I can still loads of lasers well above the 5mw range, also I`ve had a 100mw Hitachi laser at 650nm visible red that`ll cut things up quite nicely, but much prefers Black/Green or Blue surfaces, as for the green lasers they can very often be turned up well beyond their rated power they`re sold at often a ten fold increase is easily done in about 5 minutes.

 

the interesting thing with my 650nm is that it doesn`t Look much brighter than my 625nm at 5ma, and yet it cut/burn with ease, funny how the eye works :)

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the interesting thing with my 650nm is that it doesn`t Look much brighter than my 625nm at 5ma, and yet it cut/burn with ease, funny how the eye works :)

 

Your eye is most sensitive around 550-575 nm, so as you move away from that the same power will appear dimmer. That's the difference between radiance and luminosity; the latter is normalized to our eye's response (i.e. how bright something appears to us, rather than how much energy it puts out)

 

625 vs 650 is about a factor of two in sensitivty. And if the spot size isn't the same, you have to account for that, too. Plus, they eye's response to intensity may not be linear.

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You're right, it isn't. The eye's response to intensity is logarithmic. A stimulus luminance needs to be 10 times as intense to appear twice as bright. This is what gives us the massive functional range of light intensity.

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well when I take my 650nm down to a pin spot to cut things (plastic cups etc...) I need to wear sunglasses, you get serious long lasting "Spots" in your eyes after if you don`t (I only did that once and it`s gone now after about half an hour from 15 seconds exposure).

however when I make the beam colminated (as my 625 is) there`s very little difference in brightness.

I noticed that a few year ago with an IR laser, all you can actualy see is a tiny tiny red dot in the actualy laser semiconductor itself (I actualy thought it wasn`t working properly at the time) even at IR, you`ll still get visual distortion that lasts many hours (mine lasted a day or so and still isn`t 100% resolved yet).

as Swansont said Radiance and Luminosity are entirely different beasties!

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actualy I need to correct something here, the laser wavelength is 665nm not 650nm as I stated before (I just read the data sheet again).

as for safety I have an old pair of sunglasses with clip on color filters, I use Green filters for the reds.

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an interesting Test I`ve just discoved today, is to get some Thermal Printing paper, the sort used on Fax machines or some till rolls, you can identify it easily enough by quickly brushing a cigarette under the paper and it should turn Black instantly on the one side.

 

then you get a green or blue marker pen on the back of the paper and make a large mark on it, then you power up your laser and write something on the marker pen side, if your laser`s powerfull enough, it`ll print out what you wrote on the thermal side in Black :)

 

Dont try it directly on the white surface though without suitable eye protection, a good 50%+ of the beam energy will bounce back directly at you!

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  • 1 year later...

*Bump*

 

I just bought a pair of 532nm 50mw green lasers unmodified :)

they`re DPSSFD types, so I`ll keep one as it is and plan on taking the crystals and filter out the other to leave a 808nm 350mw IR laser pump diode.

 

doesn`t anyone know if this can be colminated directly?

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