Re: Star Wars - in your back yard

Feb 19, 2010 4 Replies

Speaking strictly as a former laser show tech...


  1. It takes about 60 watts of Q Switched light to kill a bug, and it doesn't really quickly kill them, it burns the wings off. Bugs fairly regularly die within 20 feet of the laser at the rare laser shows that still have that kind of power. But NO regulatory agency is going to allow that kind of widget into the backyard. Your looking at 3500$ for the galvos, And another 2500 for a decent laser in bulk, and I do mean in bulk, because at Q1 they are about

10,000$ give or take.
  1. Blueray is not going to do that, 2 combined blue-ray diodes (405 nm) running in their pulsed mode, would have a average power of about half a watt.


  1. A while ago, a government sponsored group was talking about using lasers for female only selective kills. I suspect that is where he got the idea...

  2. I love listening to the galvo bearing noise in his audio.. A lot of that is not wingbeat, its tracking loop... I suspect getting enough data for identification would require adding Doppler, and that is NOT easy. Cue Phil Hobbs...


  1. The adaptive focuser required for a kill would have to move at about 2.5 Khz... Do the math, its not cheap. they exist, but not very cost effective.

  2. Mozzies breed far faster then that thing can kill them...

The hardware there is a CNI 100-200 mW 532 nm DPSS laser, That would NOT be a kill unless you tied the bug down and focused the beam on it with a lens. The scan head is a used galvo pair from a company called Scanlab, And the Schlieren derived imaging technique is NOT easily field deployed, there is a custom mask needed inside the camera lens . What 3M gets for a 1 meter square sheet of that retroreflector would fund a 24 pack of RAID in spray cans.



If he needs 100-200 mW for tracking, that works out to about a 1 in



2000 shot at retinal damage at 10-20 feet, and a almost 100% certain damage to a human eye close in.

While someone on his team has shown considerable skill in closing the tracking loop from camera to laser, this is not viable for laser safety reasons. One shot of the kill laser would be a retinal burn in a human.



But what a viable way of getting some investor to pay you to have fun for 6 months or a year.



Schlieren for tracking:

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Steve ..


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Yeah, but couldn't you just build a big self-contained box (say, the size of a cargo container) that mechanically could only focus on things within that box (and used fences or other mechanical barriers to keep people out)?

I agree with you that as it exists now, it's pretty cost prohibitive. The cost would almost have to be taken as "cost per mosquito killed per unit time" or similar anyway -- a mosquito-killing laser system is probably quite cheap at, say, even $25k if it can sit there all night and kill 95% of the mosquitoes entering a village (but what he has right now looks like it might kill one mosquito every few seconds, which is closer to 0% :-) ).

---Joel

I wonder if they got the idea from me? My book, first published in

2000, has a very similar system used as a tongue-in-cheek example for signal level calculations.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net

Well, there goes my hopes for outdoor entertainment at a soon to be summer night. Thanks for the interesting info, though...

No,, entertainment is still possible. Xenon arc lamp, and some moist co2 to attract them, and a cheap co2 laser, mounted on a 3 meter pole, angled up at 15 degrees at 10-20 watts to kill them. just downcollimate the co2 beam, 10 micron IR does a wonderful job on flying mozzies, and 2 feet away its safe for you and 20 feet away its safe for aircraft, birds etc... 3 meters is the 21 cfr 1040.1 height for laser safety.. ;-)

Steve

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