Double Slit Experiment with White Light and one Slit colour filtered

Commando Spaz
Messages
11
Reaction score
0
What would happen if the double slit experiment were to be undertaken using white light, and one of the slits was covered by a monochromatic filter (i.e. something which only one wavelength could pass through), and apart from this there was no detector monitoring which slit each photon was coming through?
I think there are two possible scenarios:

1. The wave interference pattern is visible for the colour of the filter, however the rest of the light would display a normal particle pattern behind the slit which was not filtered, it would not be white light, but would represent the white light if the wavelength of the monochromatic filtered light were removed from it.

2. There would be no interference pattern and the particle pattern would appear on the screen, the light which came through the non filtered slit would be white, and the light which came through the filtered slit would be monochromatic.

Please explain which, if either of these scenarios would occur, please explain why or why not
 
Physics news on Phys.org
Commando Spaz said:
2. There would be no interference pattern and the particle pattern would appear on the screen, the light which came through the non filtered slit would be white, and the light which came through the filtered slit would be monochromatic.

What do you mean by this? The light coming through the slits will retain their property since there is no interference near the slits.
 
Before going any further can you explain what you think each photon of white light is. In particular do you think each are the same?

Thanks
Bill
 
bhobba said:
Before going any further can you explain what you think each photon of white light is. In particular do you think each are the same?

Thanks
Bill

I understand that white light is made up of photons of different wavelengths
 
Last edited:
Adithyan said:
What do you mean by this? The light coming through the slits will retain their property since there is no interference near the slits.

Yes, that's what I mean in the second scenario. In the first scenario, the monochromatic light passing through the filtered slit interacts with the same wavelength going through the unfiltered slit. The other wavelengths of the white light are unaffected.
 
Commando Spaz said:
I understand that white light is made up of photons of different wavelengths

That's correct - and random polarisations as well.

That being the case the solution to your query is easy.

If its the same wavelength as the colour filter of your slit you will get interference. If not it will not pass through that slit and you wont.

It looks pretty trivial to me, which is why I asked the question.

Thanks
Bill
 
  • Like
Likes 1 person
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
Back
Top