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First-time poster here, so excuse me if I commit an LPF faux pas or two, but I have a few questions about the (in)feasibility of using a 20 diode array of 5-6w modules to create a 100-120w device. That being said, please accept the following as a hypothetical thought-experiment about the practicality of DIY laser arrays as destructive weapons.
The rough idea is to create a circular array of ten 9mm modules in the fore row and a second row behind them staggered such that the beams emit from the aft array between the modules of the fore array. The structure of the array would be made of copper and several copper-water heat pipes (like those used to cool high-wattage computer equipment) would be integrated into the structure on both the interior and exterior of the circular array to draw heat to larger, external, air-cooled heat sinks.
The 20 beams would then be focused with a convex lens and straightened with a concave lens, like so:
Power would be supplied by high-drain nominal 3.7v LiMn 18650 batteries, wired in series-parallel to provide a maximum of 8.4v and a minimum of 6v once the batteries are drained. Of course, each laser module will have it's own driver, but with the recent advent of very high-drain LiMn batteries, as few as six 18650s in series-parallel could safely power the device, assuming each driver pulls 5-6A. However, I would likely use 10-20 18650s to give the device a longer period of usage before recharging or switching battery packs
Of course, such a device could easily cost 6,000-10,000 USD, but ignoring that hurdle, what other obstacles would keep this device from working?
I've never worked with high-wattage modules before, so I don't know how much cooling is necessary. I assume one heat pipe per module would be a good number to suck heat from the array and take it safely away to larger external heatsinks. Of course, making sure the heat pipes interface effectively with the array structure would be the hardest part, but I think it could be done, even in a DIY environment.
I've found what I think would be good lenses (link)--available in 50mm diameter--for the project that should be effective in focusing the array into a single beam, however, I worry that the lenses themselves could be damaged by the heat or potentially crack from rapid heat expansion. Is this something I should be worried about, even with lenses tuned to specific wavelengths of lasers?
The absolute most difficult issue would be aligning the individual modules to be perfectly parallel in their array. Is this possible with quality CNC machining and some delicate press work, or is getting 20 modules to line up and play nice just too difficult to be accomplished? Another related challenge would be getting the distance between the lenses exactly perfect so as to fight beam divergence at range, but i feel like it could be done with a fine enough adjustment method. Maybe.
Knowing a little about how light works, I'm guessing the longer the wavelength the better as far as giving the device good destructive range. What commercially available diodes in the infrared spectrum could supply this kind of wattage? Is it feasible that a DIY-er could buy them for around $200 per diode (or preferably much less)? What kind of effective destructive range could I expect with infrared? Though my research has dredged up nothing, are there any diodes in the microwave spectrum that can be purchased?
To do any amount of damage I'm assuming I would need to use continuous wave diodes, but am I wrong? Could pulsed lasers do the trick? It seems I could get a lot more wattage for my dollar with pulsed lasers like these(link), but it seems like a pulsewidth of 100ns and a duty cycle of 0.1% would result in way less effective heat downrange, not to mention the difficulty of supplying the amperage 20 of them would require. But am I wrong? Could I deliver more heat with those?
Of course, building/using a device like this would be wildly dangerous, but that's kind of the general idea. Aside from igniting clothing or surrounding environment, inflicting tiny but painful superficial burns and causing permanent blindness, would 100 watts of infrared penetrate enough to cause incapacitating damage? Could a device like this only be used on stationary targets, or would it deliver enough energy to ignite something virtually instantaneously?
The last, and weirdest obstacle that could happen would be the weakening of the beam via destructive interference (link). Is that likely/possible when concentrating multiple beams into a (hopefully) singular beam?
I apologize if talking about lasers as weapons is something generally considered taboo by LPF, but for me, it's the most interesting aspect of lasers and the trend towards ever-higher wattage diodes. I would understand if moderators decide to delete the post, but I hope we can generate an interesting conversation regarding the possibility of DIY laser weapons. Thanks for reading my novel, and please feel free to poke/burn as many holes in this crazy idea as you want!
The rough idea is to create a circular array of ten 9mm modules in the fore row and a second row behind them staggered such that the beams emit from the aft array between the modules of the fore array. The structure of the array would be made of copper and several copper-water heat pipes (like those used to cool high-wattage computer equipment) would be integrated into the structure on both the interior and exterior of the circular array to draw heat to larger, external, air-cooled heat sinks.
The 20 beams would then be focused with a convex lens and straightened with a concave lens, like so:
Power would be supplied by high-drain nominal 3.7v LiMn 18650 batteries, wired in series-parallel to provide a maximum of 8.4v and a minimum of 6v once the batteries are drained. Of course, each laser module will have it's own driver, but with the recent advent of very high-drain LiMn batteries, as few as six 18650s in series-parallel could safely power the device, assuming each driver pulls 5-6A. However, I would likely use 10-20 18650s to give the device a longer period of usage before recharging or switching battery packs
Of course, such a device could easily cost 6,000-10,000 USD, but ignoring that hurdle, what other obstacles would keep this device from working?
I've never worked with high-wattage modules before, so I don't know how much cooling is necessary. I assume one heat pipe per module would be a good number to suck heat from the array and take it safely away to larger external heatsinks. Of course, making sure the heat pipes interface effectively with the array structure would be the hardest part, but I think it could be done, even in a DIY environment.
I've found what I think would be good lenses (link)--available in 50mm diameter--for the project that should be effective in focusing the array into a single beam, however, I worry that the lenses themselves could be damaged by the heat or potentially crack from rapid heat expansion. Is this something I should be worried about, even with lenses tuned to specific wavelengths of lasers?
The absolute most difficult issue would be aligning the individual modules to be perfectly parallel in their array. Is this possible with quality CNC machining and some delicate press work, or is getting 20 modules to line up and play nice just too difficult to be accomplished? Another related challenge would be getting the distance between the lenses exactly perfect so as to fight beam divergence at range, but i feel like it could be done with a fine enough adjustment method. Maybe.
Knowing a little about how light works, I'm guessing the longer the wavelength the better as far as giving the device good destructive range. What commercially available diodes in the infrared spectrum could supply this kind of wattage? Is it feasible that a DIY-er could buy them for around $200 per diode (or preferably much less)? What kind of effective destructive range could I expect with infrared? Though my research has dredged up nothing, are there any diodes in the microwave spectrum that can be purchased?
To do any amount of damage I'm assuming I would need to use continuous wave diodes, but am I wrong? Could pulsed lasers do the trick? It seems I could get a lot more wattage for my dollar with pulsed lasers like these(link), but it seems like a pulsewidth of 100ns and a duty cycle of 0.1% would result in way less effective heat downrange, not to mention the difficulty of supplying the amperage 20 of them would require. But am I wrong? Could I deliver more heat with those?
Of course, building/using a device like this would be wildly dangerous, but that's kind of the general idea. Aside from igniting clothing or surrounding environment, inflicting tiny but painful superficial burns and causing permanent blindness, would 100 watts of infrared penetrate enough to cause incapacitating damage? Could a device like this only be used on stationary targets, or would it deliver enough energy to ignite something virtually instantaneously?
The last, and weirdest obstacle that could happen would be the weakening of the beam via destructive interference (link). Is that likely/possible when concentrating multiple beams into a (hopefully) singular beam?
I apologize if talking about lasers as weapons is something generally considered taboo by LPF, but for me, it's the most interesting aspect of lasers and the trend towards ever-higher wattage diodes. I would understand if moderators decide to delete the post, but I hope we can generate an interesting conversation regarding the possibility of DIY laser weapons. Thanks for reading my novel, and please feel free to poke/burn as many holes in this crazy idea as you want!
