A Linear Birefringence Measurement Method for an Optical Fiber Current Sensor

Abstract

In this work, a linear birefringence measurement method is proposed for an optical fiber current sensor (OFCS). First, the optical configuration of the measurement system is presented. Then, the elimination method of the effect of the azimuth angles between the sensing fiber and the two polarizers is demonstrated. Moreover, the relationship of the linear birefringence, the Faraday rotation angle and the final output is determined. On these bases, the multi-valued problem on the linear birefringence is simulated and its solution is illustrated when the linear birefringence is unknown. Finally, the experiments are conducted to prove the feasibility of the proposed method. When the numbers of turns of the sensing fiber in the OFCS are about 15, 19, 23, 27, 31, 35, and 39, the measured linear birefringence obtained by the proposed method are about 1.3577, 1.8425, 2.0983, 2.5914, 2.7891, 3.2003 and 3.5198 rad. Two typical methods provide the references for the proposed method. The proposed method is proven to be suitable for the linear birefringence measurement in the full range without the limitation that the linear birefringence must be smaller than π/2.

Polarization Properties of Solid-Core Photonic Crystal Fibers for 1550 nm

“…For fiber lengths shorter than 100 m, singlemode fibers´ birefringence is described using two orthogonal polarization modes whose phase retardation presents a uniform variation [21]. Since the characterization of the ellipticity change of a known state of polarization of light having traveled along the fiber does not supply enough information on the birefringence parameters of the sample [22], several methods based on modulation [23,24,25] and polarimetric techniques [19,26] have been devised.…”

“…Therefore most scientific literature reported for photonic crystal fiber´s polarization evaluation refers to HiBi PCFs [10,[13][14][15][16][17][18][19]. They are usually characterized by their polarization beat length, measured using a wideband lamp (group birefringence) or monochromatic light source (phase birefringence).…”

Characterization of a petrographic microscope for potential use with image processing techniques

“…In this way, the comparisons between different materials, based on their birefringence, will give more accurate and reliable results. The measurement and study of birefringence is not only useful for mineral recognition in petrographical thin sections, but it is also used in characterizing technological materials, such as liquid crystals (Li, X. et al, 2016), optical fibers (Xu, S., et al 2017), in the synthesis of metasurfaces (Achouri, K. et al, 2016), in stiffness calculations of birefringent materials (Neves, N. M., et al, 2004), in identifying the properties of collagen (Wolman, M. & Kasten, F. H., 1986), in the structural characterization of living cells (Mehta, S. B., et al, 2013), and for thickness calculation of calcite crystals in coccolith samples (Beaufort, L., et al, 2014;Gonzalez-Lemos, S. et al, 2017). The wide use of these measurements ensure multiple applications of our calibration methodology for precision characterization and comparisons, especially with a low-cost system.…”