A microscopic system for inducing and monitoring the dynamics of phase changes in a material, manifested by local changes in optical transmittance and reflectance.
One of the promising products of materials research in recent years is thin films of chalcogenides, which are already being commercialized, for example, in data storage technologies. However, due to their excellent combination of properties, their use could soon be extended to the photonics field (metamaterials or other integrated active photonic devices). The principle of inscription is a reversible change between the amorphous and crystalline phases of the material, which can be induced optically. Currently, lasers emitting in the red and infrared spectral regions play a primary role. However, as with conventional CDs, a significant increase in capacity can be achieved by moving into the blue region (Blue-Ray).
This is where scientists from the University of Pardubice want to push the boundaries of knowledge. The aim was to create a functional device with two pulsed lasers, one of which would induce the phase change in the material with a shorter, stronger pulse (pump) and the other would monitor it with a longer, weaker pulse (probe). The requirement was to be able to simultaneously monitor both the change in transmittance and reflectance of the sample, from which the dynamics of the recording is then evaluated. It was also to include the possibility of precise positioning of the samples, an imaging microscopic branch allowing monitoring of the sample surface, a fully functional detection part with an oscilloscope and a PC for controlling the system and processing the measured data.
