Towards spectral tuning of long-period fiber gratings using liquid crystals

Abstract

This paper presents some preliminary research focused on achieving external tuning through the spectral properties of long-period gratings (LPGs) using liquid crystal (LC) for potential applications in photonic sensing and in communications. We propose an LPG structure based on a standard optical fiber and on a photonic crystal fiber (PCF) surrounded with LC claddings. Experimentally, it was proved that the PCF-based LPGs have a spectral sensitivity to the external index changes about 6 times higher than in the LPGs based on the standard fiber.