Opto-thermal transport engineering in hybrid organic-inorganic lead halide perovskites metasurfaces

Halide perovskites have recently gained widespread attention for their exceptional optoelectronic properties which have been illuminated by extensive spectroscopic investigations. In this article, nanophotonic surface-engineering using soft-lithography has been used to reproduce nanostructures with enhanced functionalities. A non-invasive optical technique based on Raman and photolumines-cence (PL) spectroscopy is employed to investigate the interactive effect of the thermal and optical behaviour in surface-patterned hybrid organic-inorganic halide perovskite thin films. The thermophys-ical properties of the engineered perovskite films are extracted from the softening of the representa-tive peak positions in the Raman and PL spectra of the samples which act as temperature markers. The investigation suggests a comparatively higher rise in the local temperature for the patterned thin films resulting from their enhanced absorption. Therefore, a cross-talk between the opto-thermal transport phenomena in imprinted perovskite thin films pertaining to both enhancing device properties along with maintaining device stability is established

Inversionless gain in a lossy medium

We study gain without inversion due to coherence effects in a Doppler-broadened degenerate three-level system of a rubidium-hydrogen mixture in a miniaturized micron scale custom vapor cell. The cell miniaturization gives rise to collisions of atoms with the walls of the cell. This, combined with the high collision rate with the hydrogen buffer gas allows us to observe gain in the absorption spectra. Furthermore, we analyze the role of cell miniaturization in the evolution of the gain profile. In addition to fundamental interest, the observation of gain without inversion in our miniaturized cells paves the way for applications such as miniaturized lasers without inversion.Comment: 15 pages, 8 figures, 1 tabl

England’s Abberley-Malvern Hills Geopark as a Tourism Project

The welfare initiative has led to a creation of Abberley-Malvern Hills Geopark in the borderland of West England and Wales. It covers places of a very long geological profi le with many geosites. They are a base for a development of tourism and educational activity. It resulted in many entertainments, meetings and publications as well as new elements of tourist management, of course. Many solutions can be used for a work of Polish geoparks