Understanding Fourier Optics in Electro-Optics Lab: Theory vs Experiment

[wuid]

Hi all

Last week i had an exam in electro-optics lab.
we were given a question in optical Fourier setup (attached)

and then we have some questions about the purpose of the setup.

I claimed that the aim of the proposed setup is very similar to 4-f system for inverse Fourier transform/reconstruct the aperture.
My problem was that the focal length of the 2nd len doesn't placed exactly on the Fourier plane (displaced by less than 1[cm]). because of the experience in the lab I assumed that this minor displacement won't change much of my answer - maybe we won't get the perfect transform by means of visibility, but in general that what we will see on the screen --> the inverse transform.
yes it's contradict the theory, but as i realized that the theory have a little margins with actual experiments, I thinking maybe I am right in this case.

any help with theory and approval :) or disapproval :( will be nice.
I'm planing the rebuild this setup...

 

[mark726]

Hello,

Thank you for sharing your question and experience in the electro-optics lab. It sounds like you have a good understanding of the purpose of the optical Fourier setup and its similarity to the 4-f system for inverse Fourier transform. However, I would caution against assuming that a minor displacement of the focal length of the second lens will not significantly affect the results. Even small changes in the setup can have a big impact on the final outcome, especially in experiments involving optics.
I would recommend consulting with your lab instructor or a more experienced scientist in the field to get a better understanding of the theory and how to properly set up the optical Fourier setup for accurate results. It's always better to be sure and have a solid understanding of the underlying principles before conducting any experiments.
Best of luck with your rebuild and further experiments!