Second-harmonic generation enhancement in high-contrast micropillar AlGaAs resonator in bound states in the continuum regime

It has been shown that the use of micropillar resonators, which comprise a cylindrical semiconductor cavity sandwiched between the Bragg mirrors can substantially increase the quality factor preserving the mode volume, and thus substantially enhance the local fields. Here, we show that these structures indeed can facilitate the significant enhancement of the SHG efficiency. We provide a specific design of the AlGaAs pillar microcavity and use the numerical modelling to directly show the resonant enhancement of the SHG efficiency. We believe that the presented results would be of high interest to the nanophotonic community, especially in nonlinear optics field.

Comprehensive Studies on Amino Acid Based Organometallic L-Threoninum Cobalt (Ii) Sulfate (Ltcs) Single Crystal

By the most widely used slow evaporation technique at room temperature, L-Threoninum Cobalt (II) Sulfate Heptahydrate (LTCS) materials were grown for various applications. The structure of orthorhombic LTCS was identified by X-Ray Diffraction studies (Powder X-Ray Diffraction and Single crystal X-Ray Diffraction), this analysis has also reported the crystallinity, cell parameters (a = 5.35, b = 7.93, c = 13.71), and space group (non-centrosymmetric) of the grown material. Functional groups were affirmed by FTIR analysis. Optical analysis straightforwardly confirms LTCS crystals has greater optical transparency, and Eg = 5.6 eV demonstrates the appropriateness of prepared crystals to optical applications. The mechanical properties were validated with the aid of Vickers' microhardness measurement and that also suggests LTCS belongs to the class of hard material. In this respect, the SHG efficiency of the LTCS crystal grown is 1.25 times greater than that of the KDP crystal because Co+ ions boost the SHG efficiency of LTCS and it was tested by Kurtz and Perry's technique. Electrical results documented the good conducting properties of LTCS crystal. The LTCS substance used to treat fungal and bacterial infections and this bacterial and fungal destroying property was validated by an antimicrobial assay.

M2As2Q5 (M = Ba, Pb; Q = S, Se): A source of infrared nonlinear optical materials with excellent overall performance activated by multiple discrete arsenate anions

The introduction of coordination polyhedra containing stereo-chemically active lone pairs into the chalcogenide structures is beneficial to realize the centric-to-acentric structural transformation and further enhance the second-harmonic generation (SHG) efficiency...

Inversion symmetry broken in 2H phase vanadium-doped molybdenum disulfide

Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have received much attention in nonlinear optical applications due to their unique crystal structures and second harmonic generation (SHG) efficiency. However, SHG signals...

Synthesis, Crystal Structure, Luminescence, and Nonlinear Optical Properties of 2-[(E)-[[4-[2-(4-Methoxyphenyl)ethynyl]phenyl] imino]methyl]-4- [(E)-phenyldiazenyl]phenol

2-((E)-((4-((4-methoxyphenyl)ethynyl)phenyl)imino)methyl-4-((E)phenyldiazenyl)phenol (1) have been synthesized and characterized. X-ray single crystal diffraction study of the compound 1 reveal a monoclinic structure. Room temperature luminescence is observed for 1 in CH2Cl2 solution due to π* → π transition. The SHG efficiency by Kurtz powder technique indicating the compound 1 displayed the second harmonic generation (SHG) property.

Structural, optical, morphological and SHG studies on 8 MeV electron beam irradiated Sr(HCOO)2·2H2O crystal

Strontium formate dihydrate single crystals have been grown by the slow solvent evaporation method and subjected to 8 MeV electron beam (EB) irradiation at different doses, viz. 1 kGy, 10 kGy, 50 kGy and 100 kGy. The irradiated crystals have been studied by various techniques such as FT-IR, Raman, and UV-Vis-NIR spectral analyses, powder, and high resolution X-ray diffraction, thermogravimetric analysis (TG/DTA) and second harmonic generation (SHG) measurements. The morphological features of the non-irradiated and irradiated crystals were analyzed by SEM and optical microscopy studies. It has been noticed that the SHG efficiency increases while the crystalline perfection and thermal stability of the irradiated crystals decrease with the increase of EB irradiation dose. The results indicate a significant overall tuning of physical properties of strontium formate dihydrate crystals due to irradiation.