by lobaz » Tue Nov 12, 2019 5:45 pm
Antonio, I assume your object is diffuse, i.e., it breaks polarization. I also assume that lengths of the object and the reference paths are approximately the same, i.e., within the coherence length of the laser you use. You can check the amount of object light hitting the plate as Dinesh suggested, but 99% it is the movement. If you have some spare optical components, try putting a beam splitter to the position of the object and make an interferometer. If you are not sure, check Practical Holography, Appendix 4, how to check fringe stability.
Antonio, I assume your object is diffuse, i.e., it breaks polarization. I also assume that lengths of the object and the reference paths are approximately the same, i.e., within the coherence length of the laser you use. You can check the amount of object light hitting the plate as Dinesh suggested, but 99% it is the movement. If you have some spare optical components, try putting a beam splitter to the position of the object and make an interferometer. If you are not sure, check Practical Holography, Appendix 4, how to check fringe stability.