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."
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: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: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.
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, 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!!