Mahesh, I would like to suggest a slight modification in your experiment, not in the setup but the time periods the experiment is performed. The experiment should be performed when the earth is the farthest and then nearest to the Sun, and then over the period of the Sun's core rotation. The farthest and nearest Earth-Sun distance could be combined with the Sun's core rotation. I suggest this because of the observed varying nuclear decay rates.
During a 15 year study, the Germans identified seasonal decay rates.
Seasonal nuclear decay
"A team of scientists from Purdue and Stanford universities has found that the decay of radioactive isotopes fluctuates in synch with the rotation of the sun's core."
Varying decay rates by Sun core rotation
Some influence caused the decay rates to change.
There can be a very simple explanation for the decay rate variations, and the same mechanism could cause a difference in the experiment results you are proposing, but you won't observe them unless you match the time and Sun-Earth positions that show nuclear decay rate variations.
I suspect you will get a slight shift in the observed frequency of the light source used. Also, I suggest that vacuum permittivity be measured at the same time the interferometer experiments are run.
