If you place perpendicular polarization filters on the slits in a double-slit experiment, the behavior of the photons will depend on the specific setup and the orientation of the filters.
When light passes through a polarizing filter, it only allows light with a specific polarization orientation to pass through while blocking light with perpendicular polarization. If you have perpendicular polarization filters on the slits, it means that each slit will only allow light with a specific polarization to pass through.
In this case, the interference pattern that is typically observed in the double-slit experiment will be significantly affected. The reason is that interference occurs when waves from the two slits overlap and interfere constructively or destructively. However, if the light passing through each slit has a different polarization, they will not interfere with each other because their polarization states are orthogonal.
The resulting pattern on the screen behind the slits will depend on the specifics of the experiment. It will likely not exhibit the typical interference pattern but may show patterns corresponding to the specific polarization characteristics of the light passing through each slit.
It's worth noting that the exact outcome will depend on factors such as the polarization orientation of the filters, the coherence of the light source, and the characteristics of the screen or detector used to observe the photons. Experimental setups with polarizers in the double-slit experiment can lead to interesting observations and are the subject of research in quantum optics.