Study of transparent media using a simple digital holographic interferometer configuration

In some areas such as chemistry and biology it is of interest to have the ability to analyze transparent samples when they are subjected to changes or interactions with other media. In interferometry, these kind of tests are normally carried out with variations of a Mach-Zehnder layout where the object under study is in-line between the object beam and the camera's sensor. The latter, results in a rather complex system difficult to align and that can easily saturate the sensor, among other experimental drawbacks. This invited talk presents a simple optical arrangement based on a digital holographic interferometer with an out-of-plane sensitivity, that allows the interaction of the object beam with the transparent sample only once without the need to have the digital camera aligned in-line with this beam. The use of a neutral backscattering screen avoids saturation in the sensor and introduces the possibility of being able to control the magnification/zoom used to inspect the sample. As proof of principle we present the results of the interaction of liquids with other liquids that have small differences in their temperature and density. The versatility and potential of the proposed interferometric system can be further explored by analyzing some chemical and physical reactions and their resulting optical phase.