Destructive interference and energy

AI Thread Summary
In photon annihilation, energy is conserved and transformed into the mass of particle-antiparticle pairs, rather than disappearing. Destructive interference in light waves creates regions of zero intensity, but this does not involve photon annihilation; photons do not destroy each other through interference. In a laser beam, interference can reduce overall intensity due to the balance of constructive and destructive interference effects. High-energy photon collisions can lead to particle creation, but this process is rare and unrelated to typical light interference. Overall, the energy remains constant, merely changing forms rather than vanishing.
24forChromium
Messages
155
Reaction score
7
Where do the energy go in a pair of photons that are annihilating each other exactly? What happens when they collide with something that absorbs photons like an electron? (I think electron can absorb the e. in a photon to jump into a higher level) Would this light wave become undetectable like destructively interfering sound?

I was thinking in the context of a laser beam, suppose light waves of various frequencies are sent, the beam may be less "powerful" because of interference, or so I heard.
 
Science news on Phys.org
Destructive interference creates areas of zero light intensity (the dark regions in a classical interference patterns), but there are also areas of constructive interference (the bright regions in the pattern) where the intensity is greater than it would otherwise be. The two effects balance so the total energy is conserved.

None of this has anything to do with photons, which don't annihilate each other when the interfere.
 
24forChromium said:
where do the energy go in a pair of photons that are annihilating each other exactly?
The only way for that to happen is for them to produce a pair of particles (one is the anti-particle of the other). The photon energy goes into the mass of the pair.

This is extremely unlikely and requires very high energy photons. It is not related to interference of visible light.
 
DaleSpam said:
The photon energy goes into the mass of the pair.
Said in this way could seem that "the photons energy disappear and is transformed in something else", which is false. The energy stay the same. Better to say that 2 particles transform in other 2 particles.

--
lightarrow
 
Thread 'A quartet of epi-illumination methods'
Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
Back
Top