Lasers and the FBI

[Laserman532]

I think 1064 nm (near IR) would shoot right through the windscreen. (Correct me if I'm wrong, but I'm pretty sure that glass is transparent to 1064.) Thus, all you'd need is a converted laserscope with the KTP removed, and you'd have a source of q-switched 1064 nm IR that could create pulses in the order of many 10's of kilowatts of peak power. For your targeting and collimation, you could use a simple reflector telescope.

Bottom line: For less than $5000 you could build a device that would fit inside a van and be truly capable of permanently blinding an airline pilot on final approach. And since the retina has no pain receptors and does not respond to IR at all, the pilot would have no blink or aversion response. He'd just see his vision go black - forever. Now that's scary.

This is the real laser threat to airliner safety. But instead, we focus on idiots with laser pointers.

OK, I get it, you can distract a pilot with a pointer, and yes, at the wrong moment that could cause problems for the flight. But it's damned sure not going to cause lasting eye injury, let alone permanent blindness.

Adam

target acquisition and tracking are your technical hurdles....

[Laserman532]

mabe photonbeam can dig up the picture of my 40 watt laserscope mounted to a 360 degree turret coming out of the roof of my laser van...I did a gig for him and he has the pic...so yeah...been there done that

edit - totally self contained 6kw generator 4kw chiller - mobile unit from park to sky in 10 minutes

[buffo]

target acquisition and tracking are your technical hurdles....

Speaking purely off the cuff: start with the raw IR beam from a laserscope. Expand beam to fill the 1 inch objective lens on your telescope (that should be ~ 6X up-collimation, assuming you start with a 4 mm beam out of the YAG) and then up-collimate again through the telescope (assume a 6 inch reflector) to a 6 inch exit beam. That should yield roughly 36X total divergence decrease, and your exit beam will be something close to 150 mm. So if your initial divergence was 2 mrad, you're now down to .06 mrad. Let's just call it .1 mrad though, to account for scattering and shitty optics.

Assume you set up at a road near the end of the runway. Assume visual sighting of the plane on short final at 1/2 mile out, altitude 400 ft. That puts your distance to the plane from the ground at just under 2700 feet. At .1 mrad with an initial beam of 150 mm, the beam will be ~240 mm in diameter when it strikes the aircraft. That's just 10 inches across. Or about the size of the pilot's head.

So assuming you've fiber-fed your up-collimating telescope and have it mounted on a movable tripod, all you need to do is use the spotting scope on the main telescope to find the window for the guy in the left hand seat. Put the crosshairs on the window and pull the trigger. If you consider the peak IR pulse power is 20KW, divide by the area of the spot (24cm * 3.14 = 75 cm^2) and you get an irradiance of 267 watts per square centimeter. Pretty dangerous!

Granted, hitting the window is going to be a challenge. However, by setting up at the end of the runway and aiming back along the flight path of the incoming plane, once you get zeroed in the relative difference between the plane's glide slope and the aiming angle of the laser will be very small, only requiring modest adjustments. And once you get it on the windshield, you only need to hold it there for a few seconds to cause permanent blindness.

This is back-of-the-envelope calculation stuff here. I could be off by as much as an order of magnitude on the divergence, based on all the assumptions I made. But even if that's the case, then you just need a larger telescope to start with. Bottom line, this is definitely doable with "garage-level" technology, assuming you're already sitting on a working laserscope... (And we both know that the 20KW figure is on the low side too.)

This is what the FBI, and the FAA, should really be worried about. Because if an idiot like me can figure this out, anyone can.

Adam

[The_Doctor]

Now now, soon you two will have Igor fetching the lamps to allow you to examine your new bolt-necked Prodjallen lying on the lab table.

[Laserman532]

its all fun and games until someone looses an eye

[The_Doctor]

No worries, get Igor to put the lamp on the floor, grub around till you find it, and pop it back in again. Frankenallen will be on its feet and blinding folks in no time.

[Laserman532]

No worries, get Igor to put the lamp on the floor, grub around till you find it, and pop it back in again. Frankenallen will be on its feet and blinding folks in no time.

i guess i missed that story....

[The_Doctor]

i guess i missed that story....

Actually, so did I. There was a Pro DJ Allen, alias Prodjallen, he is a kind of mythical beast on PL, he had a laserscope I think, and did things nearly everyone but him came to regret. And I was having a lurid vision of a lurking fiend reading the cookbook just now, and plotting, scheming, rubbing its hairy hands in evil glee. Not that I think the real threats out there need PL to guide them...

[dsli_jon]

mabe photonbeam can dig up the picture of my 40 watt laserscope mounted to a 360 degree turret coming out of the roof of my laser van......

IIRC, I also have that shot somewhere.. I think I might have a 'Laser Rays' ad or something.. hafta try and diggit up.. re: Laser Van, heh, this 'un? http://www.photonlexicon.com/forums/...1598#post41598 Sorry, I know you're not keen on 'idol-worship', but.. you were just one BA laser-mofo, Pat.. ..Trades a world-class pj / install for a friggin 308 GT, Pfff.. You can't make that stuff up!

...start with the raw IR beam from a laserscope...

..Mmmyeah, but don't forget that the 'kW peaks' are also pretty-short ns-pulses.. Even if 'average power' was 150-175W of 1064 (..most you'll see out of a 'typical' LS-deck..) that's not really a lot of 'burning-power' - even low-divergence - once you cross all that atmosphere, etc.. I'd say, though, if you had 500-750W o' 1064 (average-power..) and up, you *might* start to see concerning peak-levels of IR in a cockpit.. Still, I think 30-40W of 532 filling a cockpit, even at 12mRad, is going to create a 'worse' hazard, from a flight-safety standpoint.. You're not going to be 'popping-tires', etc until you get into much, much higher powers..

.02
j

[norty303]

It's all auto-pilot these days anyway...