# So what would happen if ...



## Enigmahack (Nov 21, 2004)

You removed the IR filter with a standard 532nm laser? I wouldn't consider it simply for the fact that it'd be very bad to the eyes, but what exactly is it filtering out? Only the 1064nm wavelength?? 
*The current output is between 10-25mw, but I don't know for 100% certain*

Just curious. Again, NOT something I would do, I know it's dangerous if I don't have the right equipment and I don't have protective IR goggles. I don't need to be blind, but I AM curious as to what it would either 
A: Look like?
B: Burn stuff?
C: Be any brighter at all?
D: Have any benefits as opposed to having the filter on?


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## kongfuchicken (Nov 21, 2004)

A: Exactly the same.
B: Yeah, likely better than with the filter on.
C: not even a tiny bit more.
D: I'd be making retina-burgers and you wouldn't even know it.


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## sharkeeper (Nov 21, 2004)

The two beams are not collimated in synch with one another. What this means is your IR "leftovers" are highly divergent when your 532 is collimated and vice-versa. The IR is only dangerous very close to the laser.

The real purpose (I can see anyways) in the IR filter is to prevent someone from becoming blind by holding the pointer to their eyeball and turning it on. Yes, it *will* happen. Let me give you an example. The laser could be dropped and the MCA may beome misaligned. The pump will still be operational at full power. The natural reaction (just like with a flashlight) is to stare down the barrel while pushing the button! 

Another example would be a weak battery. Just because there is no green present does NOT mean the pump is below its lasing threshold - which could be 50 mW at least!

ALWAYS treat the laser like a loaded gun! NEVER, EVER stare into it if there's a chance of it lasing. You only get one set of eyeballs...

Cheers!

Cheers!


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## DaFiend (Nov 21, 2004)

i think that its honestly best left where it is.


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## liteglow (Nov 22, 2004)

after reading that i not so curious about remowing the filter /ubbthreads/images/graemlins/tongue.gif /ubbthreads/images/graemlins/tongue.gif

The only thing i did want to se was that my laser can burn something, (like a blac el-tape) ...


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## Enigmahack (Nov 23, 2004)

Yeah, I have to admit I was also curious but it makes sense and I wasn't about to remove an IR filter on a laser that's more than 20MW... /ubbthreads/images/graemlins/wink.gif


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## Spec (Nov 23, 2004)

You can *theoretically* get 20mW of 532 from 50mW of 808.

There have been some really interesting studies and papers written on ultra high efficiency DPSS lasers recently.

It's amazing to even think about.


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## QuestionDUDE (Nov 26, 2004)

I'm planning to remove my IR-filter in my 43mW laser pointer, I'll be testing on how it can affect the *burning*
ability and the diverge of the IR beam over distance.
But I only have a 520-540nm wavelength goggle. . . 
btw, aren't you supposed to feel *hotness* when IR is shining on you ??


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## The_LED_Museum (Nov 26, 2004)

[ QUOTE ]
*QuestionDUDE said:*
...btw, aren't you supposed to feel *hotness* when IR is shining on you ?? 

[/ QUOTE ]
With long IR (above 10,000nm or so), yes.
The IR radiation you will be letting loose when you remove the IR filter from a green laser pointer consists of two wavelengths: 808nm from the pump diode, and 1,064 from the Nd:YVO4 crystal.

Neither of these wavelengths are none too good for the eyes, so you'll want to be very, _very, *very*_ careful when experimenting. You only come with one set of eyeballs, and if you burn them out, you can't just go to your local 7-11 and pick up some "Eyeballs-In-A-Can".
In 1,000 or 2,000 years, maybe.
But not now.


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## Enigmahack (Nov 27, 2004)

It was to my understanding that the 808/1064 nm range didn't focus the same way that 532 did... So that it wouldn't be a beam the same way that the actual beam was - Is this true?

In either case, the beam output would be more dangerous in even reflection without the IR filter on so I'm sure that it's a major issue to have it removed if you don't want to have eyeball pancakes /ubbthreads/images/graemlins/wink.gif
Just a thought!


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## kongfuchicken (Nov 27, 2004)

[ QUOTE ]
*The_LED_Museum said:*
[ QUOTE ]
*QuestionDUDE said:*
...btw, aren't you supposed to feel *hotness* when IR is shining on you ?? 

[/ QUOTE ]
With long IR (above 10,000nm or so), yes.
The IR radiation you will be letting loose when you remove the IR filter from a green laser pointer consists of two wavelengths: 808nm from the pump diode, and 1,064 from the Nd:YVO4 crystal.

Neither of these wavelengths are none too good for the eyes, so you'll want to be very, _very, *very*_ careful when experimenting. You only come with one set of eyeballs, and if you burn them out, you can't just go to your local 7-11 and pick up some "Eyeballs-In-A-Can".
In 1,000 or 2,000 years, maybe.
But not now. 

[/ QUOTE ]

Even so, you'd have to be careful; without your eyes, you could get run over by a hovercraft from the local spaceport while crossing the street...


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## manyclouds (Aug 20, 2005)

Damage to the eyes READ permanent blindness !


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## badhorsey (Aug 22, 2005)

[ QUOTE ]
*QuestionDUDE said:*
btw, aren't you supposed to feel *hotness* when IR is shining on you ?? 

[/ QUOTE ]

Infra red radiation covers a fairly wide range as opposed to the visible bit of the spectrum. The heat-generating range is a far longer wavelength than that generated by the diode in a greenie.

You'll feel "heat" with a tightly collimated beam of sufficient wattage of _any_ wavelength.

But to echo the sentiments expressed thus far - and you really can't repeat them enough - you take a big risk removing your IR filter. The focussing components of a greenie are designed to focus and collimate the green beam. The IR component will fan out like a torch, meaning that the chance of catching a stray reflection are far higher.

You will not increase the burning potential of your laser. You will make it too dangerous to use.


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