<fltrz>
anyone has any original ideas to try and circumvent the diffraction limit instead of beating it?
<fltrz>
I was thinking the following: imagine a wall on the left, and an optical setup on the right, and a beam of monochromatic light shining roughly top to bottom, then imagine a gas molecule scattering the light but moving at a constant speed, say to the left
<fltrz>
the scattered light enters the optical setup and gets split by a beamsplitter, one arm is delayed by an integral and a half number of wavelengths while the other isnt. both are combined to interfere destructively on a photodiode
<fltrz>
so it registers nothing
<fltrz>
now imagine the particle collides with an invisible wall, before collision its moving to the left, but after collision its moving to the right, so there will be a slight wavelength shift... in other words one is imaging collisions
<fltrz>
the gas molecules move at approx speed of sound
<fltrz>
now consider a small volume of air and a target surface, there will be few midair collisions in the volume, but a lot on the surface to be imaged
<fltrz>
since the events on different parts of the surface are not correlated, it should be possible to image beyond the diffraction limit
<fltrz>
the light from the light source that reflects from the surface of interest has no speed of sound blue shifting because it is static, so that component (the classical microscope image) self destructs in the setup
<fltrz>
there will be some noise because of "mid air" collisions of molecules
<fltrz>
the coherence length of the laser should be longer than the free path length of molecules
<fltrz>
so the setup images speed of sound scale changes in velocity
<fltrz>
does this sound feasible?
<fltrz>
if one makes the delay in the longer arm longer (laser coherence length should be > max(path length difference, free path length gas molecules) ) then intensity on the photodiode increases because the a single molecule undergoing a collision will then produce a signal on the photodiode for a duration of D/c with D path length difference and c speed of light
<fltrz>
so essentially one tries to build a microscope with a beamsplitter, but such that the 2 fields of view are recombined without distortion and such that the whole field of view has destructive interference from both arms...
<fltrz>
as one approaches darker and darker fields of view by finetuning the setup, and using longer and longer exposure times, I expect the high resolution image to show up
<fltrz>
alternatively as a proof of concept, use one photodiode instead of a sensor, achieve the much simpler destructive interference on a small apperture before the photodiode, and then scan the 1 pixel microscope over the surface on an XY stage... if it turns out to work, one can step up to the ambition for the full field of view destructive interference microscope
<fltrz>
things that may fuck up this approach may be Raman scattering...
<fltrz>
If someone wants me to draw pictures just ask