I was able to construct time domain Optical coherence tomography based on Michelson Morley interferometer using a LED. While testing the interferometer, I used glass slide, layers of scotch tape. I was able to get fringes from. but when I try to use milk drop as a sample I don’t see any fringes. To be noted I use, 4x objective lens of NA 0.1 and I use 12bit camera. Please let me know what may be the potential reason for not not getting fringes from the Milk.
Possibly the milk particles are too small, the light randomly scatters throughout it, the returned scattered light then has random phase variations, and the fringes are washed out.
Ideally, you’ll have optical interfaces from which the light can reflect with a particular phase delay relative to the reference beam.