Thursday, March 3, 2011

Is that a UV Diode Death Star? I think it is!

I was looking for the frequencies of LED lights and found something interesting. The Wavelength (color) produced by a LED is determined by what minerals are used to dope the diode. So the spectra of the emitted light will only show a single peak. For instance using diamonds as the light source produces light at a wavelength of 235nm.
The intensity of light produced is determined by how efficiently the doping chemicals can convert electrical energy into electromagnetic radiation. Currently blue LEDs are the more efficient.
To get a white light a blue LED can be coated in various phosphors to produce a second broader peak on the spectra. The phosphors absorb light at one wavelength and re-emit it at another. Alternatively white light is produced from a combination of RGB LEDs.
Now the interesting bit, Ultra Violet LEDs with a wavelength less than 400nm can be used to sterilize water. I have seen these on camping trips but not used one. They work by radiating light ~260nm which is coincidentally the frequency of the chemical bonds in DNA causing them to vibrate. Thus the UV LEDs are able to do the same thing to DNA that microwaves do to water. Thereby mutating the DNA and cell structure until it breaks down and destroys any microorganisms in the water.
Keeping on this train of thought, is this not the same as skin cancer? I use sunscreen with a UV rating to absorb some of the UV spectrum produced by the sun thereby preventing it from mutating my skin cells to the point that they become cancerous