Measurement of the refractive index of a magnetic fluid by the retroreflection on the fiber-optic end face

Abstract

A simple method based on the retroreflection on the fiber-optic end face is developed to measure the refractive index of a magnetic fluid in this letter. The measuring principle, accuracy, and sensitivity of this method are analyzed theoretically, and high precision and resolution can be achieved in principle. Experimental measurements are done to investigate the concentration and temperature dependent refractive index of the magnetic fluid. The linear dependence relation is obtained for both cases. The thermo-optical coefficient of the magnetic fluid is measured to be around −2.4×10−4°C−1.

Quantitative control of RTM6 epoxy resin polymerisation by optical index determination

“…The light reflected at the fibre end face was detected by a photoreceiver connected to the second input port of the coupler. We can then proceed to an analysis to those used by Pu et al [10], which leads to the resin refractive index changes in terms of the thermodynamic variables variations. Kim and Su [9] proposed a method to derive the refractive index of the resin from Eq.…”

“…This evolution needed to be measured in its spectral transparency regions to characterize the reaction. For this reason, we considered a sensor, whose principle is based on the Fresnel reflection at the end face of an optical fibre [6][7][8][9][10]. When the cleaved end face was dipped into the resin, there was an abrupt change of the refractive index at the core-resin interface.…”

“…Referring to other methods described in the literature [9,10], we propose to determine the epoxy RTM6 refractive index during the RTM curing process. Heat flux and optical fibre sensors are installed respectively in the mould and inside the injected resin sample and an industrial curing cycle was applied.…”

Temperature sensor using ferrofluid thin film

“…Its magnetooptical properties have recently attracted a lot of interest of many scientists due to their potential applications (Luo et al 1999a, b;Horng et al 1998Horng et al , 2001Pu et al 2005Pu et al , 2006. It is indicated that the optical transmission of the ferrofluid is deeply related to its structural patterns under external fields.…”

Single-beam Mach–Zehnder micro-interferometer based on magnetic fluids

“…It possesses the features of fluidity of liquids and magnetic property of solid magnetic materials as well. MF is an intriguing material which has many characteristics such as birefringence effect, linear dichroism, tunable refractive index, optical scattering, and electrical properties [1][2][3][4][5][6][7]. The magneto-optical properties of MFs imply their various applications in optical field.…”