Refractive index and temperature-sensing characteristics of a cladding-etched thin core fiber interferometer

Abstract

A high refractive index (RI) sensor based on an in-line Mach–Zehnder mode interferometer (MZI) is proposed. The sensor was realized by splicing a 2-cm length of cladding-etched thin core fiber (TCF) between two single mode fibers (SMFs). The TCF-structured MZI exhibited good fringe visibility as high as 15 dB in air and the high RI sensitivity attained a value of 1143.89 nm/RIU at a RI of 1.447. The experimental data revealed that the MZI has high RI sensitivity after HF etching realizing 2599.66 nm/RIU. Studies were performed on the temperature characteristics of the device. It is anticipated that this high RI sensor will be deployed in new and diverse applications in the chemical and biological fields.

Theoretical study of the dispersion effects occurring at optical fiber connections

“…At N=100, maximum was obtained for the value p=10 -2. 16 and at the value N=10, p=10 -1.17 , respectively. N (1 -qN ) for different values of the number of connections N: at N=1000 (1); at N=100 (2); at N=10 (3) The formulas for the effective pulse duration (18) and the increment of CPD (19) were obtained with some simplifications.…”

“…The fact that rate of signal propagation in a medium depends on the medium refractive index (more precisely, on the group refractive index) should be taken into consideration. Then, it is easy to assume that the connection points can cause effects of signal distortion similar to dispersion [15,16].…”

“…Applying summation formulas (14) and (15) to expressions (16) and (17) and neglecting the terms of order of smallness less than 1, approximate expressions are obtained:…”

“…At N=1000, peak value corresponds to the probability p=10 -3. 16 . At N=100, maximum was obtained for the value p=10 -2.…”

Transformer oil diagnostic by using an optical fibre system: a review

“…The reference arm is unexposed to variations, whereas, that of the sensing arm is the opposite. The sensing arm of the MZI will be more sensitive to thermal expansion effects and temperature [20] In MI configuration, the basic concept is the interference between the beams in two arms, but each beam is reflected at the end of each arm in an MI. An MI is like a half of an MZI in configuration.…”