Modification of Higher Alkanes by Nanoparticles to Control Light Propagation in Tapered Fibers

Abstract

This study presents the doping of higher alkanes, namely, pentadecane (C15) and hexadecane (C16), with ZnS:Mn nanoparticles to create new types of in-line optical fiber sensors with unique optical properties. In this research, the phenomenon of light beam leakage out of the taper and its interaction with the surrounding materials is described. The fabricated new materials are used as cladding in a tapered optical fiber to make it possible to control the optical light beam. The manufactured sensor shows high sensitivity and fast response to the change in the applied materials. Results are presented for a wide optical range of 1200–1700 nm with the use of a supercontinuum source and an optical spectrum analyzer, as well as for a single wavelength of 800 nm, corresponding to the highest transmitted power. The results present a change in the optical property dependence on the temperature in the cooling and heating process. For all materials, the measurements in a climatic chamber are provided between 0 and 40 °C, corresponding to the phase change of the alkanes from solid to liquid. The addition of nanoparticles to the volume of alkanes is equal to 1 wt%. To avoid a conglomeration of nanoparticles, the anti-agglomeration material, Brij 78 P, is used.

Optical Properties of a Tapered Optical Fiber Coated with Alkanes Doped with Fe3O4 Nanoparticles

“…For this purpose, the optic fiber taper technology was applied. Tapers were made using a fiber optic taper element technology (FOTET) set-up, which is widely described in different papers in [ 24 , 25 , 26 , 37 ]. Manufactured TOF on FOTET is described by parameters such as: an elongation, a diameter of TOF, a torch move length and a loss for 1550 nm.…”

“…The most important parameters of the taper used in measurements are: pulled out to a length of 20.0 ± 0.5 mm, which corresponds to the diameter of the taper being around 15.0 ± 0.3μm, measured losses are lower than 0.5 dB @ 1550 nm, move of torch 5 mm. The mentioned taper with a given diameter is described in the literature as a double-clad [ 24 , 25 , 26 ], which means that the created structure retains both the core and the cladding in its structure, and the alkane with NPs forms the second cladding. Below the mentioned taper diameter, the core does not play the leading role, the whole taper waist becomes the leading role, and the surrounding environment becomes a single cladding.…”

“…During the investigation, due to the low thermal conductivity of alkanes, a temperature hysteresis between the heating and cooling processes was observed. Hence, in a next stage of the research, ZnS: Mn nanoparticles of various concentrations were added to the alkanes [ 25 , 26 ]. Doping with NPs allowed for a change in temperature hysteresis and the possibility of a faster change from the ON–OFF state, and vice versa.…”

“…This article shows a new possibility to control parameters of light propagated in TOF, by changing the location of a new magnetic mixture (C 16 + Fe 3 O 4 NPs). The basic difference between the last and new research is changing the type of NPs, we used the magnetic properties of NPs which affect alkanes, without measuring thermal properties of the mixture as in [ 24 , 25 , 26 ]. In this article, we show the possibility of dynamically changing the polarization properties at room temperature.…”