Disentanglement of sources of light needs to be done by an optical device. The two sources are immersed into a liquid container. A thin plastic film (l ~ 100 μm) is present at the surface of the liquid container, on the path between the sources and the optical device.
In situation (1), emission from source 2 goes through the liquid, through the plastic film and through the air and reaches the optical device. In this situation, emission does not suffer from reflection and is correctly identified by the optical device as coming from source 2.
This situation is not problematic. In situation (2), emission from source 2 goes through the liquid, through the plastic film and undergoes reflection at the interface between the thin plastic film (refraction index ~1.3) and the air (refraction index ~1). The refracted emission is further reflected at the surface of source 1, leading to the misidentification of the emission source by the optical device. This situation is the problematic one. We are looking for any type of solution that could help solving situation (2).
At the moment, two types of solutions are envisioned:
a. Hardware: a coating is sought to be placed on top of the thin plastic film to prevent reflection at the plastic / air interface. The challenge here is that the plastic film is thin.
b. Software: a software is sought that could be able to take the multiple reflection into account to improve source identification.
Background and