https://www.selleckchem.com/products/eft-508.html We report on the distributed shape measurement of small deformations produced along the length of an optical fiber. The fiber contains multiple waveguiding cores, each inscribed with weak continuous Bragg gratings. The distributed Bragg-reflectivity data for the fiber cores, obtained from the optical backscatter reflectometry, are used to estimate the local curvature and the position of the fiber. We successfully demonstrate the sensing of periodic microdeformations-approximately 1 µm or less in amplitude and a few hundred µm in length. Such microbends are known to cause attenuation in optical fibers, and the approach presented here can enable a detailed measurement of these microbends in applications ranging from telecommunications cable design to biotechnology, robotics, manufacturing, aerospace, and security.The intriguing physics of non-Hermitian systems satisfying parity-time (PT) symmetry has spurred a surge of both theoretical and experimental research in interleaved gain-loss systems for novel photonic devices. In this work, we investigate vertically stacked GaInP PT-symmetric nanodisk resonators arranged in two-dimensional periodic lattice using full-wave numerical simulations and scattering matrix theory. The proposed dielectric metasurface supports lasing spectral singularities with asymmetric reflection and highly anisotropic far-field scattering patterns. It offers a much broader design parameter space to control wavelength, scattering direction, and efficiency of optical emission when compared to the predominantly one-dimentional (1D) or quasi-1D structures studied so far. The proposed system with Q-factor >105 serves as a powerful platform for enhanced light-matter interaction by enabling extensive control of asymmetric light scattering, amplification, and unprecedented localization of electromagnetic fields.It is important to arbitrarily manipulate optical intensity, an important degree of freedom to