The determination of the refractive index profile in α-profile optical fibres by intermodal interference investigation

Volume Fraction Determination of Binary Liquid Mixtures by Measurement of the Equalization Wavelength

“…The difference of the phase constants β 1 and β 2 shows an extreme in wavelength dependence, which corresponds to the equalization wavelength [10]. According to Equations (2) and (3), the difference of phase constants of two modes depends on the core radius ρ and the respective refractive indices n co , n cl .…”

“…One of these interferometric methods is intermodal interference in optical fibers, which is often employed in optical fiber sensor design and can be used for characterization of optical fibers [8–10]. …”

“…Interferometric methods are optical methods which can determine the refractive index changes with mixtures’ compositions [ 7 ]. One of these interferometric methods is intermodal interference in optical fibers, which is often employed in optical fiber sensor design and can be used for characterization of optical fibers [ 8 – 10 ].…”

“…An important parameter of intermodal interference is the equalization wavelength λ e of two interfering modes [ 10 ]. For weakly-guiding optical fibers the value of the equalization wavelength depends on the core refractive index n co of the optical fiber, on the refractive index of the cladding n cl and on the core radius ρ [ 10 ]. A change of one of these three parameters can be readily detected by equalization wavelength λ e measurements.…”

<title>Intermodal interference in photonic crystal fibers</title>

“…The term intermodal interference is most often used in connection with sensors 1-,3 or when the determination of optical fiber parameters is studied 4,5 . The origin of this effect lies in the fact that the phase constants of particular modes and their derivation with respect to wavelength, β j (λ), are different.…”