Abstract:
In telecommunications, the two most important developments in the last few decades are mobile communication and optical fiber transmission. Due to the exponentially growing number of internet users and the world wide web being rich in graphics and video content, more and more channel bandwidth and ultra-fast transmission speed are required to accommodate the high demands of modern technologies. As a result of this, a lot of research was carried out in these past decades on optical fibers which appeared to be a potential candidate. Proving more promising than ever, advance in fiber optic technology further led to the discovery of photonic crystal fibers abbreviated PCFs. Expanding the application of optical fiber technology beyond communication and transmission, PCFs are nowadays used in various fields such as in medicine or automotive and for several other proposes. One such application is in sensing. Due to the dire need to monitor, sense and control useful and harmful chemicals for industrial, environmental and bio-medical purposes, chemical sensing has become an eminent subject among researchers. Hence this paper focuses mainly on two designs proposed so as to meet with the aim of designing an optimum chemical sensor with sensitivities close enough to perfection. A modified kagome design with a relatively high sensitivity of 99.98%, effective material loss of as low as 0.000263 cm−1 and low confinement of 2.394 × 10−14 cm−1 using water, ethanol and benzene as analytes is first observed while considering other parameters such as non-linearity, dispersion, numerical aperture and effective area, which are equally investigated and discussed. In the light to reduce design complexity, a second design was proposed whereby a photonic crystal fiber made up of a spider-web like cladding and an octagonal core was investigated for sensing applications. Three widely used industrial liquids and/or by-products namely; water, acetic acid and glycerol have been investigated using Finite Element Method (FEM). Extremely high sensitivities of 99.5%, 99.7% and 99.9% were achieved at 4.5 THz for water, acetic acid and glycerol respectively. In addition to the sensitivity, parameters such as Effective Material Loss (EML), confinement loss, nonlinearity and dispersion equally showed well enhanced results compared to previous related works. The results obtained were tabulated and compared to recent works published.
