The design of molecular compounds that exhibit flexibility is an emerging area of research. Although a fair amount of success has been achieved in the design of plastic or elastic crystals, realizing multidimensional plastic and elastic bending remains challenging. We report herein a naphthalidenimine–boron complex that showed size‐dependent dual mechanical bending behavior whereas its parent Schiff base was brittle. Detailed crystallographic and spectroscopic analysis revealed the importance of boron in imparting the interesting mechanical properties. Furthermore, the luminescence of the molecule was turned‐on subsequent to boron complexation, thereby allowing it to be explored for multimode optical waveguide applications. Our in‐depth study of the size‐dependent plastic and elastic bending of the crystals thus provides important insights in molecular engineering and could act as a platform for the development of future smart flexible materials for optoelectronic applications.

Recently, the nitrogen vacancy (NV) center has emerged as a deterministic single-photon source at room temperature. However, the presence of phonon sideband emission limits the use of NV centers in various quantum optical applications. Here we report a novel way to suppress the phonon sideband emission of NV centers aided with the enhancement of zero phonon line intensity using photonic crystals at room temperature. We study the photonic stop gap mediated charge state conversion in NV centers. The enhancement of phonon sideband emission from the same structures by implementing a different measurement geometry is also discussed. The studies open new avenues in studying the NV center-based quantum nanophotonics and biophotonics.

In this article, a novel low specific absorption rate (SAR) printed planar invert-F antenna (PIFA) antenna for wideband application is presented. The prototype antenna was designed to cover the frequency range between 1200 and 3000 MHz. Its radiation pattern is approximately omnidirectional, VSWR < 2, gain in the range 2À4.6 dBi, and efficiency greater than 78%. The prototype antenna exhibits a low SAR of around 1.04 for 1 g at 1800 MHz, which is less than 51% than a conventional PIFA antenna. The antenna's performance was evaluated using finite element method (FEM) and time domain method (TDM) in electromagnetic (EM) simulation tools like HFSS and CST Microwave Studio. These results are compared with measured data. The antenna's wide band covers various wireless standards like GPS/DCS/GSM1800/PCS/WLAN/Bluetooth/WiMAX/LTE. The parametric studies clarified the effect of the stub line and via's on voltage standing wave ratio (VSWR).

The silicon vacancy (SiV) center in diamond is typically found in three stable charge states, SiV0, SiV–, and SiV2–, but studying the processes leading to their formation is challenging, especially at room temperature, due to their starkly different photoluminescence rates. Here, we use confocal fluorescence microscopy to activate and probe charge interconversion between all three charge states under ambient conditions. In particular, we witness the formation of SiV0 via the two-step capture of diffusing, photogenerated holes, a process we expose both through direct SiV0 fluorescence measurements at low temperatures and confocal microscopy observations in the presence of externally applied electric fields. In addition, we show that continuous red illumination induces the converse process, first transforming SiV0 into SiV– and then into SiV2–. Our results shed light on the charge dynamics of SiV and promise opportunities for nanoscale sensing and quantum information processing.

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The spatial- and spectral-dependent optical reflectivity measurements are essential to characterize various natural as well as artificial micron-scale photonic nanostructures. However, it is onerous to measure spatially and spectrally resolved reflectivity values from such photonic nanostructures due to their size limitations. Here, we discuss the development of a versatile micro-reflectivity setup with an in situ optical microscope combined with high-resolution actuators to measure the reflectivity from areas as small as 25 × 25 µm2. We illustrate the reflectivity measurements from natural as well as artificially prepared ordered and disordered photonic nanostructures. The optical features that are hidden in the conventional reflectivity measurements are clearly resolved using the micro-reflectivity measurements. The proposed setup is also capable of measuring the polarization-dependent reflectivity and transmission of light.

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