Uncovering Hidden Dynamics of Natural Photonic Structures Using Holographic Imaging

This is the first time, to the best of our knowledge, that holographic technique was used to monitor photo for races in insect twins and face transition in non-equilibrium conditions. The advantage of this non-invasive technique lies in the fact, that it does not cause any significant disturbance to the system. This is of high importance, for instance, for non-equilibrium studies.

Nonlinear optics and holography provide insight in complex organized structures that we encounter in all scientific disciplines. These are non-destructive techniques able to interrogate such structures on a submicron scale. Knowledge of wave and geometric optics is necessary to prepare the setup, while the analysis is based on the knowledge of physics, the experiment itself, it's simpler to perform.

Since the presented experiments are perform incomplete darkness, the opportunity to follow visual signature has critical importance for the described study To begin, perform a complete sample characterization by scanning electron microscope, linear optical spectroscopy, and non-linear optical microscopy. After adjusting the room temperature, turn on the laser and check the alignment of the optical elements. Then, align the laser beam perfectly with the concave mirror.

Afterward, check and adjust the position of the optical beam expander. Next, determine the beam part that impinges on the sample, and ensure that it forms a reflex beam. Check if the rest of the beam is collected on a spherical mirror to be used to generate the reference beam.

And also, the detector is placed within the interference zone of the two specified beams. Set up an optical photographic camera for the holographic experiment. And another one to view visible changes in the Briggs-Rauscher reaction.

Additionally, set a thermal camera with a thermal resolution of 50 milli Kelvins, and a focal length of 13 millimeters. To prepare the sample for chemical reaction monitoring, place support with a flat adhesive surface on the optical table upon which the cuvette, or vessel will be placed. Then, fill the reactants into the cuvette, and mix in the cuvette, having different volumes and concentrations, ensuring that the total volume in the cuvette is 2.5 milliliters.

Next, place it on the support in the setup. After switching off the external lights, synchronize the cameras by using a chosen interval. Then, press the recording buttons and induce dynamical changes in the system of interest.

Next, observe the holographic experiment. Then, pronounce the end of the process and save the results. To check the probe hologram for appropriate settings, choose one hologram and make a reconstruction by clicking on the reconstruct button.

Afterward, change the settings to achieve the best image, and make the reconstruction again, while repeating the steps until the best settings are defined. To perform the reconstructions, choose all the holograms and apply the desired parameters for numerical reconstruction of holograms. Then, carry out the reconstructions using the reconstruct button and the interferogram by inserting the file names in the Start with/End with field, and then, by clicking the button, Batch.

Perform a visual analysis by looking for visible changes in the interference pattern. And try to match the changes in the interference pattern with results obtained by optical and thermal measurements. Next, perform a cross examination by thoroughly analyzing the images visually from both the optical and thermal cameras with the holographic reconstructions in order to reveal dynamics at the Nano scale.

In the case of the B.R reaction, the analysis of interferograms, reveals a change in the fringe pattern at the exact moment of a phase transition. The results are of particular importance, as the optical interferometric method does not cause any significant disturbance to the system, which is a vital importance for the non-equilibrium studies. Additionally, the holographic reconstruction was performed for Wings of Butterfly, Azoria Lithonia, irradiated by lasers light at 450, 532, and 980 nanometers.

The results clearly show, that the interaction of nano structures with light, generates displacement at the Nano scale within the tissues, that affect the interferometric pattern. This presented technique, opens the possibility to reveal various dynamics and self-assembly processes for the different systems at the nano and meso scale.