Reply To: Simulation setup for particle between two media.

[Guilin Sun]

If so, please refer this example https://support.lumerical.com/hc/en-us/articles/360042260213-Simplified-microscopic-imaging
TFSF is a differential technique that removes the direct illumination. If in your experiment you did not remove the direct illumination, a Gaussian source is recommended.
Please note that you are simulating random particles, so depending on the randomness, each time the result can be different if the random particles are different