6
$\begingroup$

I was reading about thermal and non-thermal radiation and I was wondering if visible light can be emitted from a non-thermal source?

$\endgroup$
10
$\begingroup$

Yes, LED's, luminescence of phosphorous (CRT screens), most of the current screen technology, fluorescent lights. They aren't a thermal source. They heat up due to the electric current but that's not the working principle.

$\endgroup$
  • 2
    $\begingroup$ Just wanted to add lasers that operate in the visible frequency range. $\endgroup$ – Neuneck Jul 26 '13 at 17:58
  • $\begingroup$ LEDs, too, produce light without much heat (i.e., the heat production is not directly tied to the light, as with black-body thermal radiation like the Sun or an incandescent bulb). $\endgroup$ – Phil Perry May 27 '14 at 18:35
  • 1
    $\begingroup$ @PhilPerry Yeah, that's mentioned in the answer. $\endgroup$ – user80551 May 28 '14 at 5:15
2
$\begingroup$

Super-continuum sources are well known non-thermal white light sources. The gist is a laser beam interacts with a specially tailored nonlinear material to generate ultra-broadband coherent light. A few references:

Supercontinuum light

Demonstration of Stimulated Supercontinuum Generation – An Optical Tipping Point

Generation of a 650 nm - 2000 nm Laser Frequency Comb based on an Erbium-Doped Fiber Laser

$\endgroup$
1
$\begingroup$

Yes. A single atom can emit visible light and certainly is not a thermal source. My favorite example of non-thermal source of visible light is the Crab Nebula (remnant of supernova 1054), where light is generated by synchrotron mechanism.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.