Revealing the Wonder of Natural Photonics by Nonlinear Optics

Nano-optics explores linear and nonlinear phenomena at the nanoscale to advance fundamental knowledge about materials and their interaction with light in the classical and quantum domains in order to develop new photonics-based technologies. In this perspective article, we review recent progress regarding the application of nonlinear optical methods to reveal the links between photonic structures and functions of natural photonic geometries. Furthermore, nonlinear optics offers a way to unveil and exploit the complexity of the natural world for developing new materials and technologies for the generation, detection, manipulation, and storage of light at the nanoscale, as well as sensing, metrology, and communication

Luminescent properties of praseodymium doped phosphate tungsten bronze

Nowadays phosphate tungsten bronzes (PWBs) attract a lot of attention due to their interesting chemical, mechanical, and optical features. Moreover, tungsten bronzes as inert inorganic solids, with incorporated rare-earth ions in their structure, show interesting and useful electronic properties. Praseodymium doped phosphate tungsten bronze (Pr-PWB) is obtained in the process of phase transformations of PrPW12O40∙6H2O (Pr-PWA) salt. The green crystals of Pr-PWB are formed after the heating of Pr-PWA in a furnace, in a temperature range from room temperature to 650 °C. In the present paper the fluorescent properties are analyzed of Pr-PWB, its precursor – 12-tungstophosphoric heteropoly acid, H3PW12O40∙29H2O (PWA) with Keggin's anion structure, as well as the intermediate – Pr-PWA salt. The luminescent properties where characterized and the obtained results showed that both samples emit in the deep blue region, indicating their potential use as a blue emitting source for white light LED's

The synthesis, characterization, behavior in the Briggs-Rauscher reaction, and photoluminescence properties of newly created phosphate-tungsten bronzed doped with cerium and praseodymium

Phosphate tungsten bronzes (PWBs), due to their intriguing and potentially valuable properties, have consistently garnered research attention [1]. In this study, we introduced two rare-earth metallic elements, namely cerium and praseodymium, as dopants for PWBs. This led to the successful synthesis of novel PWBs doped with cerium and praseodymium, which were subsequently subjected to various characterization techniques, including thermal analyses (TA), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDX), and hotoluminescence spectroscopy (PL). The behavior of cerium and praseodymium doped phosphate tungsten bronzes (Ce-PWB and Pr-PWB) [2], was investigated in the Briggs-Rauscher (BR) oscillatory reaction. The alterations in the oscillatory dynamics, brought about by the incorporation of cerium and praseodymium dopants, served as a means to distinguish between these bronzes. Additionally, this approach provided a method for assessing the catalytic properties of the bronzes. Apart from their nonlinear behavior, these bronzes also exhibited photoluminescence in the visible spectrum, specifically in the blue region

Linear and nonlinear optical response from Cicadas transparent wings

The wings of some insect species are known to fluoresce under illumination by ultraviolet light. Their fluorescence properties are, however, not comprehensively documented. In this presentation, the optical properties of unknown fluorophores naturally occurring within Cicadas transparent wing, were investigated using both linear and nonlinear optical (NLO) methods, including one- and two-photon fluorescence and second harmonic generation (SHG)

Novel tetrakis lanthanide β-diketonate complexes : structural study, luminescent properties and temperature sensing

Lanthanide β-diketonate complexes have been extensively investigated in the past, as they are cheap, easy to synthesize and they tend to form highly stable complexes with lanthanide ions. Lanthanide β-diketonate complexes have been used as NMR shift reagents, also they are good precursors for further synthesis in some more complex matrixes (such as sol-gels, polymers…), used as OLEDs and as temperature probes because of their distinct luminescence properties.1 Optical thermometry based on luminescence is an expanding field of research because non-contact temperature sensing can have different applications, such as in bioimaging, anti-counterfeiting or in industry where it is necessary to have good sensing properties in precisely defined temperature ranges.2 Here, we report novel structures of different homonuclear (Ln3+ = Eu, Tb, Sm, Dy, Pr, Nd, Er, and Yb) complexes and four heteronuclear complexes: two Eu-Tb and two Tb-Sm complexes with different ratios of the two ions. The trifluoro-acetylacetone (TFAC) ligand has been chosen for the synthesis because it is well known and widely used in complexation chemistry. Up till now, there have not been any reported structures of tetrakis TFAC complexes with lanthanides. The complexes crystallize in the orthorhombic system with Pna2 space group with four molecules per unit cell. The structure consists of a [Ln(TFAC)4]- salt with a sodium cation, where the Ln ion is coordinated with eight O atoms from the TFAC ligand. The homonuclear complexes show luminescent properties in both the visible and NIR region. The Dy complex shows temperature-dependent luminescence in the 280-380 K region, with a maximum value of Sr = 3.45% K-1 at 280 K. The heteronuclear complexes of Tb-Sm with different ion ratios also show good temperature-dependent luminescent properties in this region with maximum Sr = 2.30 % K-1 at 360 K. For the Eu-Tb complexes, it was also observed that the different ions ratios influence the temperature-dependent luminescence in the way that they can be sensitive in the different temperature regions. For a complex with a higher Tb3+ contents temperature sensing properties were observed in the 10-335 K range, with a maximum Sr value of 1.65 K-1 at 285 K. When more Eu3+ ions are present in the heteronuclear complex, it shows temperature sensing abilities in the physiological region, from 273-373 K, with a maximum Sr value of 2.70 K-1 at 353 K. References 1 K. Binnemmans, Rare-earth beta-diketonates, Handbook of the Physics and Chemistry of Rare Earths, 2005, Chapter 35, pp. 107-272. 2 C. D. S. Brites, A. Millan, L. D. Carlos, Lanthanides in Luminescent Thermometry, Handbook of the Physics and Chemistry of Rare Earths, 2016, Chapter 49, pp. 339-427

Analiza etarskog ulja plodova kumina i ukupnih polifenola u ostacima nakon destilacije

The essential oil content in cumin samples from Serbian market ranged between 2.0 and 4.0%, with 22 identified compounds, among which the most abundant were cumin aldehyde, β-pinene, γ-terpinene, γ-terpinene-7-al and p-cymene. Postdistillation cumin seeds waste material that remained after the essential oil extraction contains total polyphenols of between 30.1 and 47.5 mg GAE/g dry extract, as estimated by the Folin-Ciocalteu method. Hydroxybenzoic and hydroxycinnamic acids, as well as glycosides of flavonones and flavonoles, are the dominant polyphenols. However, according to DPPH method, the antioxidative potential of cumin postdistillation seeds waste was poor and it ranged between 0.02 and 0.04 mM TE/g. Further research will be focused on agro-food implementation of postdistillation waste material of cumin and other plants which are used for the essential oil production.Sadržaj etarskog ulja u plodovima kumina prisutnog na Srpskom tržištu kreće se između 2.0 i 4.0%. Primenom GC/MS identifikovane je ukupno 22 komponente u etarskim uljima kumina, među kojima su najzastupljenije: kumin aldehid, β-pinen, γ-terpinen, γ-terpinen-7-al i p-cimen. Međutim, kako je sadržaj etarskog ulja u plodovima kumina mali (ispod 5%), veliki deo biljnog materijala ostaje neiskorišćen. Primenom tzv. Folin-Ciocalteu metoda, ustanovljeno je da ostaci nakon destilacije etarskog ulja iz plodova kumina sadrže između 30.1 i 47.5 mg GAE/g suvog ekstrakta ukupnih polifenola. Hidroksibenzoeva i hidroksicimetna kiselina, kao i glikozidi flavonona i flavonola, su najzastupljeniji polifenoli. Na osnovu DPPH-metoda antioksidativni potencijal ostataka nakon destilacije plodova kumina je slab i kreće se između 0.02 i 0.04 mM TE/g. Dalja istraživanja bi trebalo usmeriti ka primeni ostataka nakon destilacije plodova kumina i drugih biljaka koje se koriste za destilaciju etarskih ulja u prehrambenoj industriji i poljoprivredi

Unveiling the nonlinear optical response of Trictenotoma childreni longhorn beetle

The wings of some insect species are known to fluoresce under illumination by ultraviolet light. Their fluorescence properties are however, not comprehensively documented. In this article, the optical properties of one specific insect, the Trictenotoma childreni yellow longhorn beetle, were investigated using both linear and nonlinear optical (NLO) methods, including one- and two-photon fluorescence and second harmonic generation (SHG). These three distinct optical signals discovered in this beetle are attributed to the presence of fluorophores embedded within the scales covering their elytra. Experimental evidence collected in this study indicates that the fluorophores are non-centrosymmetric, a fundamental requirement for SHG. This study is the first reported optical behavior of this type in insects. We described how NLO techniques can complement other more convenient approaches to achieve a more comprehensive understanding of insect scales and integument properties