<p>Orbital angular momentum (OAM) is generated using circular-photonic crystal fiber (C-PCF), which is used as a key solution for higher data communication. This C-PCF steadily supports 80 OAM modes and 2 linear polarization modes from 1- to 2.5-μm wavelengths with low confinement loss (CL), very high nonlinearity, and flat dispersion. The average CL is <1 × 10<sup> − 6</sup> dB / m and the dispersion of each mode is controlled in the range of 30 to 500 ps · nm<sup> − 1</sup> · km<sup> − 1</sup>. The average nonlinearity value is >1.26 × 10<sup>5</sup> W<sup> − 1</sup> km<sup> − 1</sup> at 1-μm wavelength that is essential for the generation of the supercontinuum, biomedical imaging, and several nonlinear optical applications. With all these good features, this proposed optical fiber is promising for application in fiber-based OAM high-capacity communication systems.</p>
In this paper, a surface Plasmon resonance (SPR) based photonic crystal fiber has been proposed and numerically investigated by Finite Element Method (FEM). The proposed SPR-based PCF shows higher average wavelength interrogation sensitivity than the previous structures. Different plasmonic materials have been used to show the difference in results. Liquid filled cores with metallic surface can be exited with leaky-Gaussian core guided mode. Numerical investigation of optical properties for the proposed PCF has been established by changing the designing parameters like pitch, diameters etc. The proposed PCF is simple in nature and can be easily fabricated by existing methods. Biological substances, biochemical, organic chemical analysis, bimolecules can be detected by our proposed SPR based PCF.
Combustible or harmful gasses noticeable all around are adequate to decimating a geographical region of bringing about a flame, explosion, and venomous exposure. In this paper, a highly sensitive gas sensor based on slotted-core photonic crystal fiber has been presented which can be used as a gas sensor. The guiding properties of the proposed PCF are numerically investigated by employing finite element method (FEM). The Proposed PCF contains slotted core and a hexagonal cladding where the geometrical parameters are varied to optimized. Simulation result reveals that the proposed PCF shows a high relative sensitivity of 48.26%, the high birefringence of 2.17×10<sup>-2</sup> and a lower confinement loss of 1.26×10 <sup>-5</sup> dB/m. Effective area, Beat length, Splice loss, V-parameter are also reported in this paper.