Lasers for Fun and Profit 121
Stuart of Wapping writes "This is a very interesting site, links to pages describing real-life, tried-and-tested Star-Trek/James Bond gadgets... The Laser Medical Pen, or Medpen, developed in-house by the Laser Division of the Air Force Research Laboratory's Directed Energy Directorate, is a second-generation device that provides a physician or paramedic with a unique, compact, portable, and battery-operated laser capability. The laser can cut like a scalpel as well as coagulate bleeding."
Dilberted? (Score:5, Funny)
This isn't much of a worry for me (Score:1)
Re:This isn't much of a worry for me (Score:2)
Re:This isn't much of a worry for me (Score:1)
"What? You want us to dial 911? Let me ask, what good is 911 if you're unable...to...speak?"
Laser Tag? (Score:4, Funny)
Wow, I thought laser pointers in traffic were bad.
This'll bring it to a whole new level.
Interesting... (Score:4, Insightful)
Re:Interesting... (Score:2, Interesting)
Re:Interesting... (Score:2)
Obligatory Simpsons Reference (Score:1, Funny)
Not Really (Score:4, Insightful)
Actually... (Score:2, Interesting)
High Power Microwaves? (Score:4, Interesting)
"High Power Microwave produces burnout and disruption in electronics while not affecting humans."
Yes, I realize that anything within a range of the spectrum around 2.4Ghz is considered microwave (cell phone, cordless phones, 802.11, etc.) but isn't the only reason they don't hurt people because they are relatively low power? I imagine if you pump enough power into one of those things it could start to make you boil.
Anyway, I'd hate to be one of the test subjects used in determining whether or not this actually does cause damage.
Not exactly. (Score:3, Insightful)
Microwave ovens operate at around 2.4Ghz usually... the reason they can heat up water is due to the frequency itself, and it's ability to cause water molecules to move around in the field. It's not, as some say, because it's the resonant frequency of a water molecule.
Microwave at higher frequencies could even be harmless.. depending.. the reason it screws up electronics is because of the photoelectric effect.. the microwaves end up creating lots of electric currents that burn out the equipment.
It's quite concievable that this would work yet be generally harmless to a human.
Re:Not exactly. (Score:3, Interesting)
Wouldnt this mean that we could also make a large microwave, and use it as some sort of weapon (not realy).
Also do the home microwaves use a very specific frequency?, or else photoelectric effect could short circit the hearts electric timing system.
Medevo
Re:Not exactly. (Score:1)
Re:Not exactly. (Score:2)
You don't need a "large" microwave for that. The magnetron in a typical microwave oven is more than enough to cook someone, or so I'm told. Since the magnetron emits a coherent microwave beam, you can aim it at someone's head for maximum effect.
I think FUTURAMA already demonstrated that when Leela went on a killing spree in the "What If..." episode "ANTHOLOGY OF INTEREST I" when she wanted to find out "what it would be like if I were more impulsive"?
Leela smashed a hole in the microwave oven door, turned it on and killed Bender.
I would assume there SHOULD be some safety circuits to prevent such a method for creating a portable killing machine (by using a huge battery backpack and a power inverter or just plugging it into the car's power outlet while driving). However, given the corners cut in corporate profit motives, I suspect there may be MICROWAVE TOTING MURDERERS walking the streets right now.
Seriously though, there wouldn't be too much effort to turn a Microwave oven into a DEATH TOY with a bit of physical hacking of the case, electronics, shielding, & coming up with a really portable power supply.
Re:Not exactly. (Score:2, Informative)
Nearly correct, but a bit incomplete. It is because of the frequency of the microwave photon. The energy level of a microwave photon happens to correspond to the gap in energy levels between the ground quantum state of a water molecule and higher "excited" quantum states. The microwave photon collides with the water molecule. The water molecule absorbs the energy of the photon, causing it to "jump" to a higher energy level. Once enough of these photons are absorbed by enough water molecules, the average kinetic energy of the entire group of water molecules is raised, which in turn raises the temperature.
Wrong, Frequency is not critical this time. (Score:1)
(For other things like cellphones, the ratio of wavelength to body-part size could be critical to efficiency of heating, so frequency can be critical, and is so frequently.)
The wavelength of the microwaves needs to be comparable to the size of the object which then gets an induced alternating electrical field. That alternating field drives the molecules as little syncronous induction-motor rotors. Heat being just molecular kinetic energy, it is felt as, and cooks, as, any other heat source, but inside-out.
. It is because of the frequency of the microwave photon.
NO! If you check standard texts, you will find that microwave oven performance is largely insensitive to variation in frequency, and indeed may vary within the ISM band. Domestic microwave ovens are at about 2.5GHz in the Industrial Scientific and Medical (ISM) Band out of historical coincidence (existing allocation, existing equipment) only. Note that has a wavelength of 12cm, a bit long for a molecular resonance. This is very close to the 2.4G part-15 data and part-97 ham bands. The water and water-vapor absorption is quite weak, being on the flank of the 22GHz weak resonance. Any competent microwave design book, whether for data, radio-astronomy, or diathermy, will have the tables and charts. See for example,
You can see in the diagram there that absorption does decrease from 1G to 2.5G, it's nothing like a resonance, it's considered an edge of the low "window". In the 10GHz range, we consider clouds to be lenses not opaque absorbers, and that's higher up that peak's flank.
Under the terms of my ARS radio license, I know I have to abide by federal human/radio safety standards (which will prevent me from anywhere near our full authorized power on 2.4G any time soon! Just thinking about 5W on 10G with feed and dish gain is enough to worry about.). The scarier thing is those who don't know about them are supposed to too.
The Federal standard for human / radio absorption safety is available from FCC OET RF Safety Home page [fcc.gov] ; their Consumer Facts watered down version is Human Exposure To Radio Frequency Fields Federal Communications Commission [fcc.gov]
73 de radio n1vux
Re:Not exactly. (Score:3, Insightful)
Re:High Power Microwaves? (Score:2, Informative)
Microwaves that are NOT at that magical resonance frequency just cause simple tissue heating effects, like a strong RF transmitter. At least until you get upwards in frequency toward gamma and x-rays where the energy becomes known as "ionizing radiation".
At that point, the energy can knock around the nucleotides that make up DNA and cause mutations, cancer, etc. (a Bad Thing).
Re:High Power Microwaves? (Score:1)
This seems to be one of those persistant myths...
Re:High Power Microwaves? (Score:3, Interesting)
There _is_ a resonance, and thus at frequencies near that, water absorbs stronger than other materials. If memory serves me correctly, the resonance is at around 1.4 GHz (although my mental arithmatic might be out) for the H-O-H bend. At the 2.4 GHz then, it's not having much of an effect, compared to a resonant system. But there is an increase in it's absorbtion cross section, due to that.
Were it not for the resonance, then it wouldn't be principly water that did the absorbing, and the penetration depth in a microwave would be much greater.
IIRC the 2.4 GHz was picked because the ways to generate microwaves are pretty efficent at that frequency, and the energy dispertion inside water is 3Db per inch or so.
Re:High Power Microwaves? (Score:1)
Re:High Power Microwaves? (Score:1)
The timelord went back in time and changed the oven frequency in order to save us!
He knew after 2001, radiation leaks from microwave ovens would interfere with x10 videocameras! x10 Camera Frequency [x10.com].
Even though 2.4GHz would also interfere with 802.11b, etc. [wave-report.com], stopping x10 was more important!
Future proliferation of x10 videocameras had to be stopped since the easy to use cameras only encouraged viewing nudity and thus would harm more of "the children".
Politicaly correcting history required any spectrum be sacrificed!
Besides, it really was the only way to stop the x10 pop-under ads!
Re:High Power Microwaves? (Score:2)
He had stories from other marines who had tried the same trick on humans with similar results.
Suitcase laser (Score:4, Interesting)
Hedley
Re:Suitcase laser (Score:1)
Re:Suitcase laser (Score:1)
The good old DED (Score:2, Funny)
I believe that is under the Department of Redundancy Department.
Re:The good old DED (Score:1)
The good old HERD (Score:2)
Re:The good old DED (Score:1)
Directed energy is energy which is directed to go in some particular direction -- that is, energy which is aimed at some target. This is as opposed to undirected energy, which flows forth in all directions, like a bomb.
Note that bombs with shaped charges, such as the one used to blast a hole into the hull of the USS Cole, are also a sort of directed energy, though I don't know if the Directed Energy Directorate handles that sort of thing. A shaped charge is an explosive charge whose explosive force goes mostly in one particular direction, rather than in all directions as with a conventional bomb. Shaped charges have been used at least since World War II in anti-tank weapons, though many modern tanks are equipped with a type of armor that is highly resistant -- if not impervious -- to shaped charges. Details of how this armor works is highly classified for obvious reasons.
Household chemicals? (Score:2, Funny)
Household chemicals? Ooo... so if I mix some ammonia, iodized salt, water, and ketchup, I'll have one of these? I bet my neighbors will quit making noise at 3 in the morning when they know I've got this!
Re:Household chemicals? (Score:1)
Re:Household chemicals? (Score:1)
I'm not so sure, our AK-47 didn't to sh*t. Damn Texans ain't scared of guns.
Oh oh! (Score:1, Redundant)
OUCH!
zerg (Score:2)
--start--
Hit in the ass by a laser
Livin' it up when I'm goin' down
Hit in the ass by a laser
Lovin' it up 'til I hit the ground
-Wadetemp
---end---
Coagulate? (Score:3, Informative)
Do you mean it cauterizes the wound? That is when intense heat stops bleeding. Coagulation is when the platelets aggregate to form clots. I doubt the laser is doing this.
Re:Coagulate? (Score:1)
Yes, "coagulate" (Score:1)
When we use surgical lasers, we tend use a more narrow-spectrum green beam to coagulate (I've most often used argon) -- the green light is better tuned to the absorption properties of hemoglobin (and thus a greater amount of the energy is absorbed by the blood).
The cutting beams we use can be at a different wavelength, and they also tend to have a tighter focus and will have a longer pulse (even continuous)...The tighter focus and longer pulse are all better for cutting. With something like tattoo removal, or other superficial uses, you'll tend to use a less focused beam.
Re:Yes, "coagulate" (Score:1)
Fun with lasers? RTFM for lasers... (Score:5, Funny)
CAUTION: DO NOT LOOK INTO LASER WITH REMAINING EYE!
Re:Fun with lasers? RTFM for lasers... (Score:2)
Yea but,,, (Score:5, Funny)
And yet the one thing I ask for is still missing. That's right. I want some sharks with frickin lasers attached to their heads.
Throw me a bone here, people.
Re:Yea but,,, (SPOILER ALERT) (Score:1)
ya got it wrong... (Score:1)
Dr. Evil, Austin Powers: Goldmember
Thats a hell of a pen... (Score:3, Funny)
Re:Thats a hell of a pen... (Score:1)
Re:Thats a hell of a pen... (Score:1)
Re:Thats a hell of a pen... (Score:1)
A better idea is to create a magnetic field and fill it with plasma. That would be quite easy if you could make a fusion reactor the size of a cucumber...
Ambulances (Score:1)
Re:Ambulances (Score:1, Insightful)
Just my guess, anyway.
Not Especially Useful in the Field (Score:2, Interesting)
Active Denial Technology (Score:2)
I've got one (Score:4, Interesting)
Especially a battery operated, portable Death Ray!
I just picked up a 3 Watt laser diode at a Hamfest recently. It's whats at the core of the med-pack and portable med-pens displayed. This thing is really fucking cool. It will make paper and wire insulation, plastic, etc. burst into flame from about 1/4 inch away.
The diode is made by Spectra Diode Labs (SDL) and channels 3 Watts of optical energy at 808 nanometers into a fiber optic. I have that clamped into a standard mechanical pencil to hold the fiber and allow it to be directed with some control.
The spot that appears is very scary because it appears weak red, about 5 mW of visible light energy is present but 98 % of the optical power is invisible in the infrared spectrum.
I haven't tried any home laser surgery yet, but it makes a dandy wire stripper or marking scribe. I also use it to open sealed ni-cad battery packs and change cells for walkie-talkies, etc.
Yep, Everyone should have a Death Ray!
Re:I've got one (Score:2, Interesting)
Re:I've got one (Score:4, Interesting)
I've got it mounted to the outside of a dual D-Cell battery holder clip (from Radio Shack, of all places!) with a small power switch and a current limiting resistor in series.
These are used as printer's plate thermal developing units in larger arrays.
These are also used as pumps for DPSS (Diode Pumped Solid State) lasers. I've got a nice chunk of KTP used to double 1064nm down to 532 (green), but I need to find a large piece of Nd:YVO (Vanadate) which transforms the 808 up to 1064nm.
This is how most of the green laser pointers work, they have a diode similar but smaller, putting out about 100-500mW at 808 nm and using similar crystals to transform the frequency to 532 nm.
Re:I've got one (Score:2, Interesting)
See if you can get your hands on Nd:LSB. It's a bit more expensive than YVO, but it's got a *much* higher saturation intensity, and more efficient absorption of 808nm as well
Re:I've got one (Score:1)
coherent optics r00l.
Re:I've got one (Score:1)
Re:I've got one (Score:2, Interesting)
Re:I've got one (Score:3, Informative)
The beam isn't collimated out of the fiber, so after about 1/4" or so, the beam diverges enough that it doesn't set things on fire. I have a simple collimator from a laser diode, and with a little tweaking, I can set things afire from 8 to 10 inches away!! That is REALLY cool.
Re:I've got one (Score:2)
Re:I've got one (Score:3, Interesting)
The diode package is a small 1/2" dia. gold can embedded in a slab of beryllium copper(?). I have the thing screwed directly into the positive
battery terminal on the battery clip holder.
During operation, I tend to use short bursts, and after about 10-15 minutes of blowing things up it just starts getting warm. Continuously, it would probably heat to dangerous temps within 1-2 minutes. A simple CPU cooling fan/heatsink combo would be more than adequate for continuous operation, which the diode _was_ designed for.
Re:I've got one (Score:2)
The problem with a CPU heatsink/cooling fan is that it would make the thing a little unwieldy for hand-held aiming.
Re:I've got one (Score:2)
Especially a battery operated, portable Death Ray!
I just picked up a 3 Watt laser diode at a Hamfest recently. It's whats at the core of the med-pack and portable med-pens displayed. This thing is really fucking cool. It will make paper and wire insulation, plastic, etc. burst into flame from about 1/4 inch away.
The diode is made by Spectra Diode Labs (SDL) and channels 3 Watts of optical energy at 808 nanometers into a fiber optic. I have that clamped into a standard mechanical pencil to hold the fiber and allow it to be directed with some control.
The spot that appears is very scary because it appears weak red, about 5 mW of visible light energy is present but 98 % of the optical power is invisible in the infrared spectrum.
I haven't tried any home laser surgery yet, but it makes a dandy wire stripper or marking scribe. I also use it to open sealed ni-cad battery packs and change cells for walkie-talkies, etc.
Yep, Everyone should have a Death Ray!
Wouldn't it be cheaper to buy (or scavange) the laser diode from a CD Burner, tack on a power supply and burn away?
Re:I've got one (Score:2, Informative)
This happens with about 20-30mW of laser power, about 1/100th the power of the laser i'm talking about. If you focus the laser down to a pinpoint, lasers in that class will _enventually_ heat things like dark paper, black plastic enough to just start to burn. It takes 30 secs or so to start things on fire at that power level... 3W makes em burst into flame instantly!!
COIL lasers are bad. (Score:2, Interesting)
The laser pen is cool though.
Life imitates art? (Score:2, Funny)
Anticipating the paradox... (Score:2)
Bury this post and watch to see if my prediction comes true....
Re:Anticipating the paradox... (Score:1)
I do, however, think it's unethical to test such a weapon on animals, especially when they have human volunteers for the project.
Re:Anticipating the paradox... (Score:1)
Re:Anticipating the paradox... (Score:1)
Re:Anticipating the paradox... (Score:1)
Did anyone read the disclaimer page.. (Score:3, Funny)
You people are just not doing your jobs and will have to be fragged.
Re:Did anyone read the disclaimer page.. (Score:1)
Not good for checking pupil dialation (Score:1)
Re:Not good for checking pupil dialation (Score:1)
Re:Not good for checking pupil dialation (Score:1)
Star trek device (Score:1)
Can't resolve domain name (Score:1)
Unless it's been
Thanks.
oh great, another security checkpoint failure (Score:2)
And ya know what, they aren't doing that already. One more thing to slow us down. And just how do you see a laser scalpel from a normal metal ball-point pen on the X-ray?
Here is the plan (Score:1)
Tinfoil hat mode on? (Score:2)
How many of you have read the "reports" regarding supposed cattle mutilations coupled with UFOs, and how the incisions/cuts on the carcesses seem to be made with surgical precision, but no loss of blood at the incision (ie, the cuts seem to have been cauterized)?
I know there is at least one account I have read of that described the "aliens" seen using a laser like device, about one foot long...
Re:Bruce Springsteen's Blood Money (Score:1)
Re:Bruce Springsteen's Blood Money (Score:2)
To trade is human, to hedge, divine!
Re:Bruce Springsteen's Blood Money (Score:1, Insightful)
Re:Bruce Springsteen's Blood Money (Score:1)
Seriously, Borned in the USA?
(Hint to