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Confirmed cheap multi-line 980nm/490nm pen

Sigurthr

Sigurthr

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Re: Possible cheap 2-line 980nm/490nm pen

Remember that the eye is far less sensitive to the second harmonics of the lower IR/NIR wavelengths as well. doubling 780 would result in 365nm which while still visible, requires mW for even dark adapted eyes to see, where as 490nm can be seen in the uW range.

You'd need specialty dichroic/notch/pass filters and a photomultiplier detector to really test for spurrious emision like what we'd need. Still though, good experimental effort.
 





Atomicrox

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Re: Possible cheap 2-line 980nm/490nm pen

390nm actually, but your point is very valid. OTOH 850nm doubled would be 425nm, which could be visible enough - the issue might be the low power of my 850nm laser.
 
Sigurthr

Sigurthr

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Re: Possible cheap 2-line 980nm/490nm pen

Yep, derped up the math a bit there. I really need to get more then 3hrs of sleep when I post, haha.
 
The_LED_Museum

The_LED_Museum

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Re: Possible cheap 2-line 980nm/490nm pen

I have spectrographically confirmed the existence of the ~490nm line -- and yes, it's a narrowband laser line!

980-1.gif

Spectrographic analysis of the 490nm line.


980-2.gif

Spectrographic analysis of the 490nm line; spectrometer's response narrowed to a band between 485nm and 495nm to pinpoint emission, which is 490nm.

The raw spectrometer data (tab-delimited that can be loaded into Excel) is at http://ledmuseum.candlepower.us/47/980.txt

:wave:
 
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J

joeyss

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Do I have to buy it from that seller or will any 980nm laser work cause I found one for $50 that uses 600ma of current so it must be more powerful.
 
J

joeyss

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Well I ordered a 150mw one along with a glass lens that blocks ir light 808 and 1064 have 2 % transmission. I'm guessing it blocks 980 as well? meanwhile it passes visible light 97%.
 
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Atomicrox

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No one can be sure other 980nm lasers will work, please report back after you test!

You should test to see if your IR filter is working properly with an LPM. It's likely it will work, though.
 
J

joeyss

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Atomicrox said:
No one can be sure other 980nm lasers will work, please report back after you test!

You should test to see if your IR filter is working properly with an LPM. It's likely it will work, though.
Click to expand...

I have a 1w multimode 808nm i'm interested in studying due to an anomaly in it.

There's no lens on it as it used to be a 400mw green.

I won't say what it is until I have all the data on spectrum.

If i have a camera that pics up 808nm decently well it should show 980nm right? as this one is in the dilda host and focus able so I can remove the lens if need be. If it shows up on camera well it'll be my new night vision laser. It's about 3x as powerful as the pen from the same seller so I hope i can focus the 490nm line after using the filter.
 
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joeyss

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Atomicrox said:
Cameras usually respond better to 808nm, but mine does pick up 980nm.
Click to expand...


Mine picks up 980nm like crazy in dark mode.


too add I just got a 150mw 980 and it does have a distinctive spot in a dark room.

it's not white ,but BLUE

looks bluer than my 445. It was from the same seller that had the pens.
I also got a ir fliter that came today.

It's in a dilda host so I can focus it and see what I can do with the blue line.

But it's visible.the 490m,
 
J

joeyss

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Also maybe possible IR beam shot from camera when it's dark :)

and then the cyan color I saw with a exposure from my DSLR after i put the filter on

However the laser heats up quick as it takes 2 3v li-ions

Should I precool it with my ac as my IR thermometer shows -50f from ac at this time of year to see what that does to the line?
 
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joeyss

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I looked at it without the collimating dioide lens from a few feet on so it spread out massively( checked on camera.) and the funny thing is I see a red component across it and then the blue all the way on the other side. But i don't see the red when i focus it with my camera on a dark room on the wall. Is the red another impurity? maybe near ir? I'm gonna try and focusing the blue better as I think the lens blocks some of it based on where it comes out on the dioide. It's not the same angle as the red near IR. Which I didnt need to be in a dark room to see. This might be a weak LED line too. I have another freak IR laser at 808nm but i'm keeping it secret until i get it spectroed , but it has a angular emission too as I put a ir filter over ir and let's just say this WL that comes out is much more noticeable and brighter than any of these 980 490s. If it's a coherent line i'll let you guys know. It's a 808nm 1 watt pump with no lens. used to be a 400mw green till the crystal came loose. I'm gonna get in spectroed with my physics prof in 2 weeks hopefully. You'll guys will be shocked if it's a laser line. True meaing of freak dioide. I just don't want to look like an idiot if it's a led emission.
 
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