Gun-safe 150-300mW lasers

[IceKnight366]

I meant at the time of using it, 4 separate lasers you can swap out and use the one you want at the time.

Alan

Yea that would be pretty cool. But if each one had a linear driver from 5-200mW, was waterproof, and had a good zeroing capability I imagine that would get pretty expensive! Don't tempt me .

 

[Atomicrox]

You need a single mode diode, else the dot will be a big line after a few tens of meters. That limits your power to around 200-300mW, unless you go for violet (which would suck because your eyes can't focus it properly).

IMHO your best bet for visibility, dot quality, ruggedness and low power is this: https://sites.google.com/site/dtrlpf/home/diodes/pl520-520nm-laser-diode

At 50mW the dot will be visible for many km and the beam will be visible during the night.

You could use a two mode driver with a low 5mW mode and a high 50mW mode.

 

[IceKnight366]

You need a single mode diode, else the dot will be a big line after a few tens of meters. That limits your power to around 200-300mW, unless you go for violet (which would suck because your eyes can't focus it properly).

IMHO your best bet for visibility, dot quality, ruggedness and low power is this: https://sites.google.com/site/dtrlpf/home/diodes/pl520-520nm-laser-diode

At 50mW the dot will be visible for many km and the beam will be visible during the night.

You could use a two mode driver with a low 5mW mode and a high 50mW mode.

Thanks for this information Atom! This is definitely something I'm going to keep my eye on! Was the beam in those pictures a simple 50mW? My 532nm 100mW laser (which is probably more like 80mW as I haven't LPM it) isn't near that bright. Maybe mine is just cheap hah. Here is a picture of mine:

To leave open the possibility, do you have a reference for a high mode of 200mW that still has great dot quality, visibility, and ruggedness? I was also thinking more along the lines of a dial where you have the entire range of the mWs, not just two modes. Is such a thing feasible?

 

[Atomicrox]

Pictures are a very poor judge of real life brightness. 50mW doesn't give a beam that solid but it's certainly very visible at night/on a poorly lit room.

If your 532nm was cheap it might be anything from 10mW to 150mW... luck of the draw.

I used "mode" in two different meanings:
-Single mode as in TEM, which determines the quality/divergence of the dot. You need single mode.
-Two mode driver as in high and low power modes, just like those used in flashlights. The low mode would provide low current and the high mode would provide high current.

It's possible to make a driver with a pot so you can dial the current, but you'll have to do some research.

I still think 200mW is way too much for this. 50mW of green will be brighter than 200mW of blue/red/violet anyways, and you won't find a single mode green diode at 200mW. You could push the diode I linked to 100mW if you're lucky, but IMHO it's best not to because your application will already put extra stress on the diode. And you want a 3 elements lens to improve the dot quality, which takes some 25% of the power.

 

[Rifter]

I would stay away from DPSS for gun mount. I would go with a single mode 520nm in the 50-100mw range should be more than bright enough with excellent divergence.

 

[IceKnight366]

As I think about it more, I think a dial would not be the best bet. Because of the recoil, there might be movement on the dial without it locking in place. Would it be possible to do a 3 mode driver of 5mW, 50mW, and 100mW using a different diode from the PL520 (and obviously different from the 520nm)

Cronic, you mean I wouldn't be able to dial it down low enough to hit 5mW or that you can not have the low setting at 5mW on a two mode driver?

Just more clarification, I do realize a 520 has some additional benefits, but I am really trying to go for 445.

Does anyone have any accerate footage of what a 50-100mW 445 would look like without fog? That is, what i could expect to see with it? It's hard to download videos while here in Greece.

Thanks again guys for all this help.

 

[Atomicrox]

As I think about it more, I think a dial would not be the best bet. Because of the recoil, there might be movement on the dial without it locking in place. Would it be possible to do a 3 mode driver of 5mW, 50mW, and 100mW using a different diode from the PL520 (and obviously different from the 520nm)

Cronic, you mean I wouldn't be able to dial it down low enough to hit 5mW or that you can not have the low setting at 5mW on a two mode driver?

Just more clarification, I do realize a 520 has some additional benefits, but I am really trying to go for 445.

Does anyone have any accerate footage of what a 50-100mW 445 would look like without fog? That is, what i could expect to see with it? It's hard to download videos while here in Greece.

Thanks again guys for all this help.

Yes it's possible to do a 3 mode driver, you can even do that with the PL520 if you happen to find an efficient one.

445nm is a bad idea:
-Too much beam visibility vs. dot brightness.
-Looks slightly blurry at a distance.
-Fluoresces things.
-By my experience you need around 200mW of 445nm to be similar to 30mW of 520nm - both have a clearly visible beam, but not "solid". 200mW of 445nm is on the edge of being a fire hazard with flammable materials.

Sorry I was not clear. I'm talking about higher power diodes. The 1W+ type. The lowest you can get them to lase is around 150mW if I recall correctly.

I have no experience with mode drivers so I will bow out here. :beer:

My 462nm will lase around 30-40mW at threshold, but it's very unstable there :/

 

[Pi R Squared]

Some of what were're talking about here is and isn't practical for mounting on a AR15, it needs to be reasonably small such as a C6 or similar size in a durable and water resistant host. Forget about a linear driver or adjustable power, these are fine in a lab laser but not for this purpose. Two or more different lasers as I suggested before would be good but are not necessary.

Alan

 

[IceKnight366]

Sorry I was not clear. I'm talking about higher power diodes. The 1W+ type. The lowest you can get them to lase is around 150mW if I recall correctly.

I have no experience with mode drivers so I will bow out here. :beer:

Ah oka, thanks for the clarification.

Yes it's possible to do a 3 mode driver, you can even do that with the PL520 if you happen to find an efficient one.

445nm is a bad idea:
-Too much beam visibility vs. dot brightness.
-Looks slightly blurry at a distance.
-Fluoresces things.
-By my experience you need around 200mW of 445nm to be similar to 30mW of 520nm - both have a clearly visible beam, but not "solid". 200mW of 445nm is on the edge of being a fire hazard with flammable materials.



My 462nm will lase around 30-40mW at threshold, but it's very unstable there :/

Sorry, it sounded as if you said you can see the 445 beam TOO much and yet not as much as 30mW of 520 (unless you go 200mW of 445). Do mean the beam would be so visible at 50-100mW that you couldn't be able to see the dot and thus where you are aiming?

I feel like the blurriness isn't too much of a problem if I keep it fairly close (say 50-70 yards? What do you think?). Moreover, I think you might be able to adjust your eyes to it with practice. And I'm not worried about having a "solid" beam as I understand the problems with going that high for a gun sight. Just so long as the beam is visible.

What about if I went 473nm? I don't really have much knowledge on these exotic ranges yet, but it seems between 445 and 520 and thus might eliminate some of those problems with blurriness, Fluoresce, and lack of beam visibility at lower mW (50-100). The thing is I desire a blue colored laser far more than a 445 specific. So I would be more than comfortable experimenting with nm's.

Some of what were're talking about here is and isn't practical for mounting on a AR15, it needs to be reasonably small such as a C6 or similar size in a durable and water resistant host. Forget about a linear driver or adjustable power, these are fine in a lab laser but not for this purpose. Two or more different lasers as I suggested before would be good but are not necessary.

Alan

Thanks for keeping this in reality Alan as I can only talk theoretical. That's really disheartening though . I got all hyped up thinking I could have a mW output adjuster. Are you saying the laser would be too fragile if outfitted with a 2 or 3 mode mW adjuster? However, I'm not too sure how small it would have to be. I mean, if we're talking about a pistol sight yes, it would have to be significantly small. But on an AR-15 I feel I could get away with making it a bit larger - perhaps 6-8 inches in length. I don't know if that makes things any more feasible, but just what I was thinking.

Im going you be in London for the next 5 days so I don't know about my connection there. I may. Not be able to respond for that time, but we'll see!

 

[Pi R Squared]

No not too fragile, just larger, you either need a larger host or something like a project box and that's just not practical for this purpose. You don't want to be adding too much weight to your rifle. Have a look at this C6 build I did more than a year ago and scroll down near the end of the first post, there are some photos to show how small it is.
http://laserpointerforums.com/f65/assembled-m140-c6-pic-heavy-83543.html
This is about the size I recommend you try for, except I think it should have a remote pressure pad switch.
Pressure Pad Switch

Alan

 

[IceKnight366]

No not too fragile, just larger, you either need a larger host or something like a project box and that's just not practical for this purpose. You don't want to be adding too much weight to your rifle. Have a look at this C6 build I did more than a year ago and scroll down near the end of the first post, there are some photos to show how small it is.
http://laserpointerforums.com/f65/assembled-m140-c6-pic-heavy-83543.html
This is about the size I recommend you try for, except I think it should have a remote pressure pad switch.
Pressure Pad Switch

Alan

Oka, the visual really helps. Yes, you are right about weighing done the AR-15 too much. As well as weight displacement would be off. However, I think I would be comfortable going 1-2 inches longer (the picture with you holding it in your hand was perfect visual). So do you think you could fit together a durable waterproof host (1-2 inches longer than the C6 if need be) that has a 2-3 mode driver, can output a max of around 50-100mW of 445 (or 473), and can be zeroed in? LoL, this is getting pretty specific, but I guess that's good!

EDIT: oh and I checked out that pressure switch and it's very interesting. But it says on there that it will reduce the laser output by 15% no? I don't know if that's worth it. It's a cool acquisition, but I don't think THAT quick of access to the laser is that important. I feel you should already have it turned on if you're going to use it. In a bad scenario the last thing you want to do is take time, no matter how small amount, to turn on an accessory unless absolutely necessary (I'm thinking like a flashlight if you literally can't see anything).

 

[Pi R Squared]

oh and I checked out that pressure switch and it's very interesting. But it says on there that it will reduce the laser output by 15% no? I don't know if that's worth it. It's a cool acquisition, but I don't think THAT quick of access to the laser is that important. I feel you should already have it turned on if you're going to use it. In a bad scenario the last thing you want to do is take time, no matter how small amount, to turn on an accessory unless absolutely necessary (I'm thinking like a flashlight if you literally can't see anything).

What? Do you hold and fire your rifle with only one hand or what?

Alan

 

[IceKnight366]

What? Do you hold and fire your rifle with only one hand or what?

Alan

To turn on accessories, yes. Do you own? How do you do it?

EDIT: I'm not leaving out the possibility of using the activation pad. But if the laser I'm aiming to get caps at 50mW, a 15% decease from that may not be worth it. Hard to tell at this point but I'm not taking that option off the table.

What do you think about my last post though? Am I on the right track?

 

[Atomicrox]

Sorry, it sounded as if you said you can see the 445 beam TOO much and yet not as much as 30mW of 520 (unless you go 200mW of 445). Do mean the beam would be so visible at 50-100mW that you couldn't be able to see the dot and thus where you are aiming?

I feel like the blurriness isn't too much of a problem if I keep it fairly close (say 50-70 yards? What do you think?). Moreover, I think you might be able to adjust your eyes to it with practice. And I'm not worried about having a "solid" beam as I understand the problems with going that high for a gun sight. Just so long as the beam is visible.

What about if I went 473nm? I don't really have much knowledge on these exotic ranges yet, but it seems between 445 and 520 and thus might eliminate some of those problems with blurriness, Fluoresce, and lack of beam visibility at lower mW (50-100). The thing is I desire a blue colored laser far more than a 445 specific. So I would be more than comfortable experimenting with nm's.

What I meant is you need 200mW of 445nm to get a beam similar to 30mW of 520nm. The actual dot will be much less bright, because Rayleigh scattering is inversely proportional to the 4th power of the wavelength.
When the beam is too bright in relation to the dot it's much harder to be sure where the dot is, and in your case much easier for the target to notice where you are.

Blur depends on your eyes, but it's always worse with blue/violet. At 10m 445nm looks slightly blurry to me. At 200m it's too blurry to be useful for spotting a target.

473nm is DPSS - easy to break and highly unstable. Same goes for 532nm. There are some "high WL" blue diodes, but they are hard to find at low powers and very expensive.

I really think 520m is the best way to go here.

 

[IceKnight366]

What I meant is you need 200mW of 445nm to get a beam similar to 30mW of 520nm. The actual dot will be much less bright, because Rayleigh scattering is inversely proportional to the 4th power of the wavelength.
When the beam is too bright in relation to the dot it's much harder to be sure where the dot is, and in your case much easier for the target to notice where you are.

Blur depends on your eyes, but it's always worse with blue/violet. At 10m 445nm looks slightly blurry to me. At 200m it's too blurry to be useful for spotting a target.

473nm is DPSS - easy to break and highly unstable. Same goes for 532nm. There are some "high WL" blue diodes, but they are hard to find at low powers and very expensive.

I really think 520m is the best way to go here.

Thanks for your continuing to help out Atomic.

I'm totally getting what you're saying, but it's hard for me to relate because I don't own a 520. Could you maybe speak in terms of 532? That is, how many mW of 445 would I need to equal the beam visibility of say a 50mW 532? Also I think ultimately at this point I just want at least a visible beam. Even if a 50mW 445 isn't nearly as visible as a 30mW 520 (this looks like a 30mW 520 right?: Green 30mW laser beam during nightly snowfall - YouTube) as long as you can see a beam, I think I would be happy. Is there a semi clear visible beam at 50mW of 445? 75mW?

As far as the blurriness at 200m goes, that is annoying but I probably won't be using a laser at that distance. I might use it at 100m (125 max) but more than that I'll probably be using a scope. Does it matter how many mWs you're using? What I mean is, would a 200mW 445 look more blurry at 200m than a 50/75mW 445 at 200m? Or is that irrelevant?

I guess the reason I'm shying away from the clear advantages of a 520 is because I already own a 532 and will be purchasing the Surefire X400 ultra with a 532 5mW laser eventually too. And given how a 520 is essentially green, I want some variety hah. I think given how blue stands out less too gives it a very slight tactical advantage as well (so it's not all bad hah). And blue is my favorite colour hah.

It sounds like getting one of those 473s is pretty hard and out of the question then. Was worth a shot.

 

[RYDorDIE278]

some may disagree but i think 400mW of 445nm would be good for your application with a 3 element lens probably be close to a 50-70mW greenie IMO, i wouldnt know but its just a guess from the difference in brightness in my lasers, My 200mW 520nm is about the same beam visibility as my 1.8w 445 BUT the dot is very intense and alot brighter on the 445nm