First time post - question about laser safety / aircraft

[Djinn]

Greetings,

Until recently, I'd never owned a laser beyond the cheap "keychain" sort. When my wife told me that she needed a decent laser to use as a pointer for her presentations, it sounded to me like she said "Go shopping for lasers, and have fun!" which is not something you hear from your wife too often, so naturally I took advantage of the situation.

After some research, I made two purchases from Optitronics; two handheld green lasers. A 5mw for my wife, and a 40mw for myself. According to the handwritten testing results included with the lasers, the output of the 40mw model actually averages around 52mw, so I got a nice bonus there. The 5mw laser is easily brighter than other 5mw units Ive seen.

Like I said, I'm a bit of a newb... I'm still awestruck at being able to see the green laser beam in a lit room, and even more amazed when using it outdoors at night.

I'm paranoid about pointing the laser at the sky... Realistically, if I am making a conscious effort to avoid shining the beam anywhere near visble aircraft, is it possible for me to hit a distant aircraft by accident? Is it possible that my 52mw laser could affect the pilots of an aircraft inside a cloud, invisible to me from the ground?

I suspect I'm being paranoid, but that's why I'm soliciting answers from the experts. Many thanks.

 

[ElektroFreak]

It is possible, but usually you can see even distant aircraft by their lights. Also, if the aircraft is too distant the light from your laser will have diverged to the point of being not at all hazardous to the pilot. I doubt if it would even be perceptible.

 

[Asherz]

Gratz on your purchase from Optotronics, it's nice to meet a new member who has actually researched a good place to buy a decent laser from, and is actually concerned about safety and respecting the hobby! I'm sure you'll be a valuable member

As for safety, just do a general check of the sky before you shine your laser making sure there aren't any aircraft you can see or hear, and you should be fine, like Elektro said the laser will probably be way to diverged (dot too large) by the time it reaches the plane and also it's not too powerful so in the unlikely chance it happened to hit something it would be hardly noticeable.

I shine my 170mW green up there all the time, only for a minute or two but just use your head, a little common sense and you'll be fine

Oh and welcome to the forum

 

[lasersbee]

to the Forum...

Yes... it is refreshing to see a new member who knows how to
research some basic info and be able to use common sense...
You will find a lot of knowledgeable members here and a ton of
Laser Related info...

Enjoy the Forum...


Jerry

 

[Tabish]

As long as you don't see an airplane where you are pointing, it's pretty safe.

As for airplanes hidden behind clouds, I would assume that the laser beam would be too diverged by the time it reaches the plane. Plus the thick clouds would weaken the beam significantly.

 

[Djinn]

Many thanks for the info, all. As I suspected, I was being paranoid, but it's often best to err on the side of caution. I'm married, so it's unlikely that I'll ever own anything resembling the gadgetry described in your signatures, but I'm glad this forum exists for us lightweights as well.

I have one more question that's a little more technical in nature... And I'm not sure that it's worth starting a new thread. I have another 5mw green laser... I believe I bought it on DealExtreme for about $10. I fully expected it to be a piece of junk, and I wasn't disappointed. It worked... but the brightness fluctuated, and I constantly have to fiddle with the encasement to keep it going. And going on the assumption that my newer 5mw laser (from Optitronics) is actually 5mw, then this $10 laser was way less than 5mw. I get the sense that DealExtreme lasers are universal crap, but I've only bought the one.

The $10 DX green laser takes about 30 seconds to warm up. During this time, it emits a faint red-laser glow. After about thirty seconds, the red gradually shifts to green, and eventually it reaches "full" brightness. How does a green laser emit a red glow when warming up?

 

[bobhaha]

Correct me if im wrong guys.. but i believe this is a crystal alignment problem.. IR or infared looks like a dim red to our eyes. Green lasers have an "IR Pump" diode which emits IR light, this light hits the crystals in the laser assembly and doubles the frequency to ~532nm (wavelength). If the crystals are dislodged or misaligned this could be the problem.

BTW yes DX is a pretty bodgey place to buy lasers, especially if you want up-to-spec lasers or anything with desent quality.. not saying its crap, some members have bought a few great lasers from DX in the past.. but I would go for a more reputable company

PS: NEVER LOOK DOWN THE LASER EVEN IF ITS EMMITING DIM RED LIGHT!! the diode pump IIRC is approx 500mw in power for a 100mw green laser... so that means for a 5mw its around 25mw IR which is totally unsafe to look at!!

hope that helped! -Adrian

 

[pseudolobster]

The only real risk to aircraft is when they're landing. If you shine a laser into the night sky, the worst that could possibly happen is you hit the bottom of the aircraft, and the pilots in the cockpit won't see it at all.

This whole thing with news reports going on about the danger of blinding pilots with lasers only applies to jackasses sitting outside an airport, waiting for landing planes and specifically trying to shine it into the cockpit, trying to cause a crash.. Even then it's not really a huge issue, since most landings are done entirely on autopilot, though there is an inherent risk. Unfortunately two or three jackasses have turned a non-incident into a majorly hyped news story, threatening the hobby for the millions of responsible enthusiasts.

I really wouldn't be worried about hitting a plane in-flight, chances are no one will ever notice or care.

 

[ProjMan]

According to the handwritten testing results included with the lasers, the output of the 40mw model actually averages around 52mw, so I got a nice bonus there.

50mw is unsafe to use--especially indoors--without laser safety goggles. It's more than enough power to cause permanent eye damage from an eye hit from both direct and reflected exposure to the beam.

I'm paranoid about pointing the laser at the sky...

The ILDA has some resources on this. The first is specifically relevant to pointers while the second is aimed at laser show operators.

Laser Pointer Safety - Tips on keeping laser pointers safe and legal
http://www.laserist.org/files/Lasers-and-aviation-safety_2pt2.pdf

 

[Deleted member 8382]

I'm sad to hear you got a bad unit from Dealextreme, because usually their 50mW less pointers are nothing near crap. It's my first option for green lasers under 50mW.

Buy their 50mW true green laser pointer for 20$ and tell me if the difference you paid for the Opto one was worth or not. I ensure you it's not