View Single Post
einfall is offline
Dec10-12, 09:34 AM
P: 11

MICROSCOPY: Imaging a field of radiated light and it's source

Thanks very much for your response - you're right, my previous question was quite unclear.

I have a micron-scale particle under lamp illumination which is also scattering laser light. I want to compute what the scattered field and particle "look like" with a specific numerical aperture under 75x magnification.

I can calculate the scattered field for any point/plane in space, so my current solution is to compute the field for a plane sitting tangentially on the particle.

I'm confusing myself because the lamp light and the scattered light both need to expand up through the solid-cone angle defined by the numerical aperture, but the scattered field is radially dependent and diverges while the lamp light is effectively collimated over this length-scale (at least I think this follows). How to go about replicating what would be "seen" on a CCD camera is the problem that's bugging me, especially because it seems like it ought to be the straightforward bit.

I know this doesn't specifically address all your questions, but I hope it clarifies the issue.

Also note: right now I'm completely ignoring the fact that the field is viewed through an aperture about 1mm above the particle, and for now I'm ignoring diffraction effects (nice Airy rings etc.)