Hollow-core photonic crystal fiber based edible oil sensor

Abstract

A hollow-core photonic crystal fiber for sensing an oil includes a hexagonal core wall, a cladding region, and a circular layer. The hexagonal core wall defines a hollow space, where a core diameter is equal to a distance between two opposing inner vertices of the hexagonal core wall. The cladding region includes a circular cladding segment and up to four cladding arms, where the up to four cladding arms extend from the circular cladding segment to four outer vertices of the hexagonal core wall. An inner wall of the circular cladding segment, the up to four cladding arms and an outer surface of the hexagonal core wall define up to four wedge shaped air gaps. The cladding region has an inner radius with a range from 2.0 up to 2.4 times the core diameter and an outer radius with a range from 2.1 up to 2.6 times the core diameter.