Final answer:
The interaction in question is related to photonic refraction and absorption, where light is bent due to varying indices of refraction or absorbed at different depths, enhancing the contrast between an object and its background.
Step-by-step explanation:
The student's question refers to the interaction of light with matter and how it affects the visibility of an object against its background. When the background is lighter or darker than the center due to the interaction of light with the material properties, we are dealing with phenomena like photonic absorption, photonic reflection, and photonic refraction. Reflection occurs when light bounces off a material, refraction happens when light is bent as it passes through a material with a different index of refraction, and absorption is when a material captures the energy of a light wave.
In the context of microscopy, as described in the background material provided, when light rays pass through a sample with different phases, leading to interference that enhances contrast, the correct answer to the student's question is related to photonic refraction. The varying index of refraction between the object and the background causes the light to bend differently, which in turn affects the phase of the light waves and results in the superimposition of these rays to produce interference patterns. Absorption can also play a role when photons are absorbed more readily at certain depths or by certain materials, as in the case of silicon and the varying penetration of blue and 1 μm photons.