Design and Optimization of All-Dielectric Fluorescence Enhancing Metasurfaces: Towards Advanced Metasurface-Assisted Optrodes.

The need for miniaturized biological sensors which can be easily integrated into medical needles and catheters for in vivo liquid biopsies with ever-increasing performances has stimulated the interest of researchers in lab-on-fiber (LOF) technology. LOF devices arise from the integration of functional materials at the nanoscale on the tip of optical fibers, thus endowing a simple optical fiber with advanced functionalities and enabling the realization of high-performance LOF biological sensors. Consequently, in 2017, we demonstrated the first optical fiber meta-tip (OFMT), consisting of the integration of plasmonic metasurfaces (MSs) on the optical fiber end-face which represented a major breakthrough along the LOF technology roadmap.

Low-cost multiple FBG interrogation technique for static applications.

In this Letter, a low-cost interrogation technique for multiple fiber Bragg gratings (FBGs) is demonstrated. The design utilizes the major advantage of the distributed feedback lasers, which is tuning their emitted wavelength by current modulation and temperature variation. The sensitivity of this method and the influence of optical losses on the measurement have been carefully studied, and an accuracy of 5 pm is achieved.