Conference Agenda

The influence of rapid thermal annealing (RTA) onto chalcogenide Ge-Sb-Se thin films is reported, focusing on changes in optical properties. These materials possess broad mid-infrared transparency covering the most critical absorption bands for (bio)chemical sensing and high third-order optical nonlinearities for potential applications in nonlinear photonics. The parameters of the RTA process within this study include the annealing temperature, heating rate, and the two sample processing methods – one by placing the sample inside the graphite susceptor and the other by simply laying the sample onto the silicon wafer. Selenide thin films were found to undergo a shift of the absorption edge upon the RTA, resulting in an optical bandgap energy increase (bleaching effect) and a notable refractive index decrease. As a result of structural relaxation, such changes show a great potential of RTA in fine-tuning of optical performance of chalcogenide thin films and planar chalcogenide waveguides. The authors acknowledge the IBAIA (101092723) Horizon Europe project, the ANR AQUAE (ANR-21-CE04-0011-04) project of the French National Research Agency (ANR), and project No. 22-05179S of the Czech Science Foundation (GAČR) for financial support.

Random laser (RL) based on Rhodamine 6G (Rh6G) doped silica xerogel, fabricated by a conventional sol-gel (SG) synthesis, was observed around 590 nm, in a large band typical from dye RLs. Different from other previous works, where the xerogel is just impregnated or infiltrated of dye solution, here the Rh6G was added during the SG synthesis. The obtained material was grinded using a mortar and a pestle, and the resulting powder was carefully packed in a sample holder and pumped at 532 nm using a 6 ns pulsed laser. We used spectral and images measurements to perform statistical analysis and describe experimentally the Parisi replica breaking symmetry (RSB) phenomenon in a complex system. These results show that RSB obtained from images is a promising method for RL characterization. Indeed, by calculating the RSB maps, we demonstrate that the RL emission is not a homogenous process, depending on the scattering and gain properties of different regions.

In the last few years, quantized nanolaminates (QNL) have become increasingly popular as a metamaterial in the development for optical coatings. Experiments were often performed using IBS or ALD coating techniques, which yield excellent accuracy but are very time consuming to coat. By using a magnetron sputter system with rotating substrate table, we are able to produce these layers at very high deposition rates and to use these nanolaminates as standalone high index material in optical designs. Due to the properties of QNL to increase the band energy and thus shift the absorption edge into lower wavelength ranges, it is possible to create designs in the UV range that would not be possible with simple Ta2O5-SiO2 material combination in regular designs. In this work we show a selection of different designs such as anti-reflective coatings, mirrors and short pass filters at wavelengths from 266-355nm which covers an important range in laser applications.

Two-dimensional transition metal dichalcogenides (2D TMDCs) have gained significant attention from the scientific community due to their exceptional properties, making them extremely attractive for optoelectronic and photonic applications. However, many exfoliation or synthesis techniques yield 2D crystals with limited crystalline quality and/or small lateral size. Here, we report a facile Au-assisted exfoliation method, yielding high-quality, large-area monolayers with lateral sizes of hundreds of micrometers. A self-assembled monolayer of (3-aminopropyl)triethoxysilane (APTES) is employed to improve the adhesion between the 2D material and the target substrate, dramatically improving the yield and reliability of the exfoliation process. The monolayer nature of the final sample is then assessed by means of Imaging Spectroscopic Ellipsometry (iSE), which enables a quick and reliable thickness mapping over millimeter-sized areas