The curvature- or bend-sensing response of long-period gratings (LPGs) UV inscribed in D-shaped fiber has been investigated experimentally. Strong fiber-orientation dependence of the spectral response when such LPGs are subjected to bending at different directions has been observed and is shown to form the basis for a new class of single-device sensor with vector-sensing capability. Potential applications utilizing the linear response and unique bend-orientation characteristics of the devices are discussed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ao.43.005425 | DOI Listing |
Biomater Sci
December 2024
FZU - Institute of Physics, Czech Academy of Sciences, Na Slovance 2, Prague 182 00, Czechia.
Recent advances in optical sensing technologies underpin the development of high-performance, surface-sensitive analytical tools capable of reliable and precise detection of molecular targets in complex biological media in non-laboratory settings. Optical fibre sensors guide light to and from a region of interest, enabling sensitive measurements of localized environments. This positions optical fibre sensors as a highly promising technology for a wide range of biochemical and healthcare applications.
View Article and Find Full Text PDFNanophotonics
July 2024
Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Tianjin 300350, China.
We propose and demonstrate the simulation and fabrication of an all-fiber orbital angular momentum (OAM) mode converter capable of generating first- to fourth-order modes simultaneously, which is realized by inscribing a cascaded preset-twist long-period fiber grating (CPT-LPFG) in a six-mode fiber utilizing a CO laser. A new segmented Runge-Kutta method is proposed to simulate the preset-twist long-period fiber gratings. By calculating the twist angle and relative coupling coefficient for each pitch and then solving the coupled mode equations utilizing the Runge-Kutta algorithm.
View Article and Find Full Text PDFRandom lasers with vector modes have garnered widespread attention due to their unique polarization and phase properties and the absence of cavity-defined longitudinal modes. In this work, we propose and demonstrate an all-polarization-maintaining (PM) random fiber laser (RFL) based on a half-open cavity that can simultaneously generate linearly polarized fundamental modes and higher-order modes. Then a cylindrical vector beam (CVB) of azimuthal polarization is generated by the mode superposition method with mode purity exceeding 93.
View Article and Find Full Text PDFBroadband high-order mode converters play a fundamental and crucial role in mode division multiplexing systems. Unfortunately, there have been no reports on achieving broadband mutual conversion between high-order modes using long-period fiber gratings (LPFGs). In this paper, based on the concept of "stepwise" progressive conversion (SPC), a double-sided exposure fabrication method of LPFGs to achieve broadband mutual conversion between high-order modes is proposed and demonstrated.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!