Infrared Lasers: Do They All Burn?

[Ablaze]

If you had a focusable laser attached to your gun sight you would shortly find out what focus you preferred it at and keep it there. Trying to find someone that sold a laser at, say, a 12 degree spread, however, would be well neigh impossible. You would want one with the ability to focus so you could experiment just after getting it.

 

[BrittanyGulden]

If you had a focusable laser attached to your gun sight you would shortly find out what focus you preferred it at and keep it there. Trying to find someone that sold a laser at, say, a 12 degree spread, however, would be well neigh impossible. You would want one with the ability to focus so you could experiment just after getting it.

Understood, hm so how wide of a degree spread can I achieve? As much as your eyes can view, which is a bit less than 180 degrees correct? Now that would take quite the set-up to be able to "beam" out there @ your 250 yard target and be able to "flood" your IR illuminator that full 180 degrees all the way to your 250 yard target.


SO just find a Host W/ that is focusable. I take it there are "ranges of focus" as you noted "12 degree spread"

 

[BrittanyGulden]

You would be able to set it to the range you would require, you shouldn't have to mess with it for every shot, though the option would certainly be there. Better to have the option and not need it, than to need it and not have the option.

No idea how they offically classify the LED illuminators. It would be "flood" vs. "throw" though.

Understood,

Some clarification on Infrared: SO "Infrared" is broken up into 3 sections which include: Near Infrared (NIR), Mid Infrared (MIR) & Far Infrared (FIR). From my understanding, most "Night Vision Scopes" use FIR?

I was recomended using an "NM" in the 900's, which sits in the NIR part of the Infrared Range-instead of the FIR range which most other night vision optics are at.


900 nM: I understand that the Human Can see EM radiation up to 760 so why do I need to be in the 900 nM range? I mean, In theory I could go 761 right? Maybe not, but you get the idea of my point.

SO just exactly what Range am I looking for when I decide what "nM" (wavelength to choose)? IR extends from .74 micrometers to 300 micrometers. Now In my application, I need a wavelength that Humans or the animals I will be hunting can not see correct.

As noted before, Humans can see up to 760, so my range should be between 761nM to 300 Macrometers correct?

SO why in the 900's?



I do know that IR is being replaced with Thermal as Thermal gives the operator a more clear image as it defies outlines, correct? So maybe I should look into gearing my Camera towards Thermal VS IR.

According to the EMS, "Thermal" looks to be around the 100 macrometer range, not sure the entire range, but the 900 nM I was recomended was far from it.

I am going to see what "Thermal" goes down to but I assume it's not as low as 900 NM.

Maybe I was suggested using the 900 range because Camera's can only view so much of the Infrared Spectrum? I thought they could view the whole thing though.

 

[Ablaze]

With the proper optics you could theoretically make it spread out as much as you like, however with the standard focusable lenses on lasers you can expect to have the ability to spread the light out about as quickly as a flashlight does.

Someone here probably knows more than I do about focusing lenses. From what I have seen most lasers with a focusing lens have about the same range of focus.

To address your new post:

808nm is a common wavelength, and most humans can see that as a dim red light. No one can see in the 900 range, but cameras still can. You could shoot for higher wavelengths, but you would need more expensive equipment in that case. at ~940nm you could use practically any digital camera.. including your iphone if you have one.

 

[BrittanyGulden]

Please see Post #51.

Alright guys, so I spent the whole night on "Hack A Day" & look what I came across:

LucidScience - Build the LASER NIGHT VISION - Page 1 of 13

Click on this link & there you will find almost exactly what I am in the process of making.

Monitor: Not sure why he didn't just use a Digital Camera as it would have served as a "ZOOM" and a way to pick up IR & transmit it onto the LCD Sreen. He did note this: "Unfortunately, camcorders and digital still cameras cannot see infrared light as they have built in glass filters that block out almost all of the infrared light in order to allow the visual light spectrum to be processed much better."

Did he not know that he can just remove the IR filter attached to the CCD to be able to do this? Now he has to use an additional instrument to "ZOOM" and another instrument to view the IR. In his case, he used a Scope & his Lap Top.

Another quote from his article: "The lower the lux rating on the camera, the more light it will be able to collect, so a camera rated for 1 lux or even lower will make an excellent imager for a night vision system."

Lux Rating? Can't say I recall seeing this on Digital Cameras. Definately something I should look for, unless "Lux Ratings" are just on Security Cameras ONLY?

His IR Laser Illuminator used in his instrument: 850nM @ 250mW.

What is really great about this article is that it lists examples which can help me choose what equipment to use. For example, check out Figure 25 on Page 13 of the article. The Pictures gives a great view of what his IR Laser Illuminator can achieve. Noted below the picture are specs. He notes that "at 100 feet, the laser spot can be adjusted to a width of about 20 ft across."

On Page 13, he noted that, "250mW is capable of distances @ 1000ft." LOL, sounds pretty weak to me, how about 1000 yards?!

Another quote from his article: "If you are looking to purchase a laser pointer style laser for night vision experimentation, then choose one that allows the collimating lens to be adjusted of fully removed. The goal will be to spread the beam out to an area of several feet in diameter at a distance of several hundred feet."

Spreading out the beam is definately going to be a task. He talks about spreading the beam out per foot, while I need it in yards.

 

[Ablaze]

That looks like a great resource. Now that you have a good idea of what you need you might consider asking for it in the buy, sell, trade section of this forum. There are people there that will custom make a host for your laser so it will fit on your rifle.

 

[BrittanyGulden]

That looks like a great resource. Now that you have a good idea of what you need you might consider asking for it in the buy, sell, trade section of this forum. There are people there that will custom make a host for your laser so it will fit on your rifle.

Anything will a cylindicular housing/shaft will work which most Laser Hosts Provide. I already have the "rings" for mounting the Lasers, it's just a matter of what type I get. Wonder if it'd be better to buy or make one myself. I'm still wondering why an Nm in the 900's. See post # 51

thanks, Tyler

 

[Sigurthr]

I don't know who told you humans can only see to 760nm. I can easily see 808nm with no problem. It's dim, sure but it certainly is NOT invisible. Up in the 900s, the light really IS invisible.

 

[Ablaze]

See post #51?, lol see post #52. Or Sigur's reply, you can see that too.

 

[BrittanyGulden]

LOL, sorry.

Understood,

Still, the Infrared Spectrum goes to 300 Macrometers, so why 'only' 900's.


I take it the longer the wavelength, typically the more expensive, so you guys are recomending me I go with the 900's because it's just "right over" what I need and would provide me with I need (a laser that niether humans or my target can see).

I mean why spend the extra money when I don't have to.

right?

 

[BrittanyGulden]

LOL, sorry.

Understood,

Still, the Infrared Spectrum goes to 300 Macrometers, so why 'only' 900's.


I take it the longer the wavelength, typically the more expensive, so you guys are recomending me I go with the 900's because it's just "right over" what I need and would provide me with I need (a laser that niether humans or my target can see).

I mean why spend the extra money when I don't have to.

right?

Yeah, I am curious to see what most Camera's can see up to. I am sure it'd take an "expensive" or special camera to be ale to see up to 300 macrometers

 

[Ablaze]

Yes, it's more expensive to find something that detects further up on that scale. Cameras that can see 940nm are everywhere. I expect that lasers that output above 1064nm are probably expensive and rare too... at least I've never heard of one.

I say use the best equipment for the job. Why try to go over 950nm when it profits you none?

 

[Sigurthr]

1064nm comes from pumping Nd:YAG with 808nm. If you removed the KTP/LBO crystal from a 532nm DPSS laser (and then fixed the optics to work without it) you would have a 1064nm laser. The longer (>1000nm) wavelengths are used in the communication industry for fiber optics mostly. Finding a laser over 1064nm (aside from a CO2 laser) that has enough power for your application would be hard to do and very expensive.

Right, 940nm is inexpensive and "just over the threshold" into invisible. Longer wavelengths of IR require more complex equipment to detect as well. For example, FIR (thermal vision) requires that the sensor element be thermo-electrically cooled lower than background temperature in order to function. Basically, the chip has to be kept in a micro-refrigerator inside the camer in order to function.

Everything (all matter) above Absolute Zero temperature gives off FIR to some degree. In order to sense FIR you have to reduce the FIR that you and your device give off.

Longer wavelengths also propagate differently in air, as there are certain frequencies which air and water vapor absorb strongly. (This is how microwave ovens work, microwaves are just slightly longer in wavelength than FIR.)

 

[Cyparagon]

It's micrometers - with an I.

Cameras can see up to around 1100nm. Nothing happens in the 15-300µm range that I'm aware of. I can't think of a single light source (except for an exotic laser maybe) that emits in that area. Thermal imaging can be from 3-15µm, and pretty much everything emits light in this area.

You want 900s because LEDs are available in that area.

 

[bennett326]

Yes, it's more expensive to find something that detects further up on that scale. Cameras that can see 940nm are everywhere. I expect that lasers that output above 1064nm are probably expensive and rare too... at least I've never heard of one.

I say use the best equipment for the job. Why try to go over 950nm when it profits you none?

way wrong there... sorry co2 lasers are 10,600 nm and pretty cheap too

sams laser faq

now a co2 wouldnt be practical here but just so you are informed ....


btw dont say things your unsure of dont want to confuse people

 

[BrittanyGulden]

Yes, it's more expensive to find something that detects further up on that scale. Cameras that can see 940nm are everywhere. I expect that lasers that output above 1064nm are probably expensive and rare too... at least I've never heard of one.

I say use the best equipment for the job. Why try to go over 950nm when it profits you none?

Exactly, however as far as power goes (mW) I am definately going to be using something a bit more powerful vs the one the guy used in that article & "flooding" the IR Illuminator out more than 10 ft across.

My Girl needed to stop at Best Buy to pick up some Ink so I decided to sneak over to the Cam's & was amazed how well some could Zoom. An employee came up to me & asked what I was doing & to my suprise he kind of understood. However, for some reason he didn't understand I was to be using this device strictly at Night for Night Vision, as he kept telling me I needed to remove the IR filter. Hm, hope he figured out that at night, there would be no visible light so the IR wouldn't be an issue in my application. Anyways,

Digital VS Optical: Is this a "one or the other" thing or do Camera's come with both options. Problem with Digital Zooms is that it really isn't a true "zoom," it just enlarges the pixels & @ longer distances, it can definately sh*t on the image quality. In my application, Long Distance Zooming will be key, so finding a Camera W/ a kick-butt Optical Zoom is the way to go, eh?