808nm laser visibility

[Trevor]

I´m actually speaking about laserdiodes. Not gaslasers. Was reading an article about that a feew weeks ago. But it was german so I have to find it first an translate for you. Will take a look tomorrow as i´m going to bed now. If i find it, i will post it.

I can use Google translator.

And you still have yet to offer conclusive proof on how infrared laser diodes emit in the wavelength range we know as the "visible spectrum."

[citation needed]

-Trevor

 

[InfinitusEquitas]

@Trevor - http://laserpointerforums.com/f41/o-ilke-63981-2.html#post927770

 

[Trevor]

Yeah.

Today I learned that "dirt atoms" in a laser die give coherent emission... :tired:

@honeyx: The above statement is sarcasm. You're still an idiot.

-Trevor

 

[Cyparagon]

You simply can check this yourself if you own a really death IR diode and a nightvision. The diode will still emit some visible red light but absolutely no IR.

I could put a dead IR diode on the spectrometer, but he'll say my spectrometer just isn't good enough.

Take a LPC 815 and check with your IR filtered military nightvision the amount of IR.

I could explain to him that a small portion of the red (since it is close to IR anyway) leaks through and registers on the sensor, but he'll just give another lame excuse.

An IR laserdiode that wend LED will still produce the same amount of visible light like before it wend LED.

I could ask for a source for this wild claim, but he'd dodge the question.
I could kill an IR diode to see if I see a difference in output, but if I don't he'll just say I need an eye exam.

Only with a high quality IR filtered nightvision you will notice the the difference. Or of course with an LPM.

I could put a dead IR diode on my meter, but he'll say my meter isn't good enough and it's not really dead.

I could go through and debunk all that nonsense. What good will it do? Make him look even more like a fool? I doubt that's possible.
Maybe if I'm bored this weekend.

 

[honeyx]

I could put a dead IR diode on the spectrometer, but he'll say my spectrometer just isn't good enough.



I could explain to him that a small portion of the red (since it is close to IR anyway) leaks through and registers on the sensor, but he'll just give another lame excuse.



I could ask for a source for this wild claim, but he'd dodge the question.
I could kill an IR diode to see if I see a difference in output, but if I don't he'll just say I need an eye exam.



I could put a dead IR diode on my meter, but he'll say my meter isn't good enough and it's not really dead.

I could go through and debunk all that nonsense. What good will it do? Make him look even more like a fool? I doubt that's possible.
Maybe if I'm bored this weekend.

Funny isn´t it? I´m to tired now to quote each part of it. just one thing.

I could explain to him that a small portion of the red (since it is close to IR anyway) leaks through and registers on the sensor, but he'll just give another lame excuse.

Yes i will because you a claiming 650nm is close to lets say 750nm. Sure its as close as green to red and blue to green and all are close to near IR.


Well what about laserdiodes not needing a collimator. I guess someone else already found an article in english a while ago. http://laserpointerforums.com/f44/laser-diodes-collimated-without-lenses-28866.html

Unfortunally this article isn´t aviable anymore, but the principle is simmilar to using microlenses for stacked laserdiodes.

http://lib.semi.ac.cn:8080/tsh/dzzy/wsqk/SPIE/vol5636/5636-666.pdf

Just the lenses being directly ached on the diode.

And back to IR. Simply take a black (for humans eyes of course) IR filter that lets IR pass let´s say 95%. But a really good one where just IR passes through and visible light is totaly blocked. No more visible light anymore but still a big spike on your spectralmeter. So if your IR Diode puts out 200mW and even by passing the filter just 100mw are coming out, you still should see some glowing if your eyes are capable of seeing IR. To compare drive the Diode with such an amount of current it puts out just 100mW and and watch directly at it.

Now I´m really going to sleep.

 

[Cyparagon]

IR filter that lets IR pass let´s say 95%...

Let's not kid ourselves. It still wouldn't convince you.

You're in for quite a collection of red bars, sir.

 

[honeyx]

And now anybody can explain the difference between a Fabry Perot and a Distributed Feedback Laserdiode? Or still not? Let me guess...

Let's not kid ourselves. It still wouldn't convince you.

Really. So looking at 100mw IR comming directly from a laserdiode and seeing some glowing while seeing at 100mw behind a filter and seeing nothing dosn´t prove anything?

So who of us is the fool? Tell me what´s the difference between 100mw filtered and 100mw unfiltered ir? If you can see IR you will notice no difference, but if you can´t you will notice a big difference.

So this is then all you can say?

It still wouldn't convince you.

Well then. It´s also not convinced lightspeed is the fastest and it´s also not convinced neutrinos really exist. So Einstein and the rest of sientists are also just fools and trolls. Do you belive in god? Prove that. And prove he really exist. Maybe by shooting a picture of him with a spectrometer or a defraction grathing.

Nevertheless. It will be way more easier to compare 100wm filtered and 100mw unfiltered IR.

Why do you think there are black collimation lenses for IR lasers?

Just for fun?


Use that one and tell me if you still see some glowing comming out of your IR laser.

You're in for quite a collection of red bars, sir.

I don´t really care. The times where people were called witches and burned just because they had a different point of view are fortunally over

 

[Trevor]

Please acquire a scientific article that states that spontaneous visible emissions from and infrared laser diode are the consequence of impurities in the die.

And I thought they made these in clean rooms...

-Trevor

 

[Cyparagon]

The times where people were called witches and burned just because they had a different point of view are fortunally over

Science isn't about a point of view.

Why do you think there are black collimation lenses for IR lasers?

That looks like GaAs (like this one), and it won't pass near IR. Your Googling has failed you yet again. Collimation lenses for near IR lasers are almost always clear.

you a claiming 650nm is close to lets say 750nm. Sure its as close as green to red and blue to green and all are close to near IR.

Even though safety goggles may be rated to pass blue and block green, green is close enough to blue that some will still pass. If I see some green even through goggles that block 99% (OD2) does that mean I'm not really seeing green, I'm really seeing the blue that the green laser makes?

Let's not kid ourselves. It still wouldn't convince you.

You missed my point here... ENTIRELY. This language barrier is really kicking your ass. So please read carefully.

Nothing I do will change your mind. I could show you with more of your own experiments that you are wrong. It does not matter what evidence I show you. Even if I got 30 experts to tell you that you are wrong, you would dig your heels in further.

Science is about drawing conclusions from evidence you are presented with. You have already drawn your conclusion, and no amount of evidence will change that - therefore, you are not practicing science, your are trolling.

 

[honeyx]

That looks like GaAs (like this one), and it won't pass near IR. Your Googling has failed you yet again. Collimation lenses for near IR lasers are almost always clear.

You are comparing a collimating lens for laserdiodes with a GaAs collimating mirrow for a Co2 gaslaser??? Yeah :wave: that must be the same And even if it´s a lens not a mirrow. Where is the cavty? It more looks like just a window rather than a lens or a mirrow.

Nothing I do will change your mind. I could show you with more of your own experiments that you are wrong. It does not matter what evidence I show you. Even if I got 30 experts to tell you that you are wrong, you would dig your heels in further.

Indeed. You won´t change my mind. The experts probably yes, but not you. And thats the point that worries you most.
If I´m wrong then I´m wrong and I can live with that and even admit that i was wrong, but....

There is no need for me to prove you something as you even didn´t take the time to read something abour Farby-Perot and Distributed Feedback Laserdiodes.

Fabry-Perot laser diode is an oscillator in which two mirrors are separated by an amplifying medium with an inverted population, making a Fabry-Perot cavity. Standard diode lasers are Fabry-Perot lasers.

Fabry-Perot laser diodes are the most common type of diode laser and are the most economical, but they are generally slower and more noisy than distributed feedback (DFB) lasers.

And they are just speaking about the amplified light. Not to mention about the bandwith of the not amplified noise comming also out of the diode.

So I won´t post any sientific articles. Belive what you want. Just maybe take a look at this Prof debuts miniature laser diode for fast networking ? The Register

and google a bit for professor Denis Deppe and his laserdiode. Or is this also a bit to much efford for you?

 

[Cyparagon]

You won´t change my mind.

And that attitude will earn you no respect and get you nowhere.

There is no need for me to prove you something as you even didn´t take the time to read something abour Farby-Perot and Distributed Feedback Laserdiodes.

That doesn't make any sense. I've provided proof that you can see IR. You have provided no proof that you cannot. Whining and giving ridiculous excuses won't prove your point. Go away.

Saying you won't prove anything just tells us you can't.

 

[honeyx]

And that attitude will earn you no respect and get you nowhere.

Ahh that´s the whole point. You suffer from being not respected? Hm well. Thats your problem but not mine.

It´s you that can´t respect others having a different opinion than you and whining about not being able to change their mind so they agree with you.

That doesn't make any sense. I've provided proof that you can see IR. You have provided no proof that you cannot. Whining and giving ridiculous excuses won't prove your point. Go away.

Where exactly did you provide the proof i can see IR? Did you watch through my eyes while providing your proof? Yes. That makes really sense.

Saying you won't prove anything just tells us you can't.

It just tells you i´m already bored about repeating myself and telling you to read yourself a bit about Fabry-Perot laser diodes. You simply ignore it and thats a sideeffect of your ignorance and the feeling not being respected.

 

[Trevor]

honeyx, you're saying we're all wrong and have been wrong the entire time we've worked with IR laser diodes. It your job to cite sources and "educate" us, not merely say "lololol ur rong nd you're're coutnry scuks!!!111"

You still have presented no material exhibiting that impurities in laser dies cause coherent emissions. I suggest you do so.

-Trevor

 

[Bluefan]

according to the CIE 1931 photopic eye sensitivity function and the CIE 1978 Judd−Vos-modified photopic eye sensitivity function the sensitivity of the human eye for 810nm is either 1.8366 E–6 or 1.8365E–6 normalised to the 550nm response.
Conclusion: 810nm is for the average people visible but even half a watt of 810nm will look as dim as a microwatt of 550nm.

The response for 790nm is around 7.466 E–6, and I can confirm that a Ti:sapphire laser at 790nm of a few 100mW is about as bright as a standard indicator led. I verified the output with a spectrometer, but such a laser doesn't have a measurable wideband emission, so it's really the 790nm light I saw.

A very usefull document: http://www.google.nl/url?sa=t&sourc...sg=AFQjCNFxw7vpb1avQxCl55p10oYCnwhBkA&cad=rja

 

[honeyx]

And you guys simply can´t stop. I´t was not my intention to educate you and never said something like "lololol ur rong nd you're're coutnry scuks!!!111" Again. Where did i say that? Point me to it.

Sorry but have to quote.

You still have presented no material exhibiting that impurities in laser dies cause coherent emissions. I suggest you do so.
-Trevor

Didn´t I or you simply didn´t look at the links i gave you? Do I have to quote all the external surces? Well i guess we will then have a problem here with copyright. Actually there is nothing specific to find about IR laserdiodes. But there is enough material telling in general about noise within a bandwith around the specific weavelenght that is produced by laserdiodes caused by impurities. There is enough info about the more impurities in laserdiode the more noise it produces and how they are trying to aviod it. You will find info about the bandwith of the noise and so on.

A Fabry-Perot laser diode ampliefies also the noise in a specific bandwith depending on the quality of the mirrows, so a bit of this noise is also coherent. The rest not but also emitted.

Ok, enough said. I´m not your teacher. So you have the world wide web to go into detail.

 

[honeyx]

according to the CIE 1931 photopic eye sensitivity function and the CIE 1978 Judd−Vos-modified photopic eye sensitivity function the sensitivity of the human eye for 810nm is either 1.8366 E–6 or 1.8365E–6 normalised to the 550nm response.
Conclusion: 810nm is for the average people visible but even half a watt of 810nm will look as dim as a microwatt of 550nm.

The response for 790nm is around 7.466 E–6, and I can confirm that a Ti:sapphire laser at 790nm of a few 100mW is about as bright as a standard indicator led. I verified the output with a spectrometer, but such a laser doesn't have a measurable wideband emission, so it's really the 790nm light I saw.

A very usefull document: http://www.google.nl/url?sa=t&sourc...sg=AFQjCNFxw7vpb1avQxCl55p10oYCnwhBkA&cad=rja

That´s the first really usfull info. So ok. If i was wrong about the range then I admit i was wrong. No big deal. However this doesn´t imply laserdiodes do not have some sort of noise that can range up to the visible area.