Recent progress of fiber loop mirror-based sensors in China Jiliang University

Abstract

The authors overview recent progress of fiber loop mirror based sensors in China Jiliang University. With the unique characteristics of fiber loop mirror made by various inserted fibers, fiber loop mirror based sensors have the potential to be exploited in a variety of wide applications.

Sensitivity characteristics of high-birefringence Sagnac interferometer sensors

“…Optical fiber Sagnac interferometer (OFSI) is one of the most attractive and common used fiber devices in fiber communication and sensors owing to its simple structure, ease of fabrication and flexible applications [1][2][3][4][5][6][7][8][9]. Especially, the OFSIs based on high-birefringence fiber (HBF) are widely studied as sensors for various physical parameter measurements such as strain, temperature, curvature, twist, pressure, refractive index and so on [2,[4][5][6][7][8]. In these studies, great efforts are focused on the goal of improving the sensitivities of the sensors.…”

“…In these studies, great efforts are focused on the goal of improving the sensitivities of the sensors. For example, sensitivities of OFSIs incorporating of diverse HBFs like panda fiber, elliptical core fiber, elliptical cladding fiber, bow-tie fiber and D-type fiber were compared [6]; Special treating processes such as chemical etching, tampering and side-polishing were also applied to the HBF to improve the sensitivities [6]; Recent years, high-birefringence photonic crystal fibers (HB-PCFs) as well as liquid-filling induced HB-PCF were employed in the OFSIs [2,7]; Besides, fiber gratings including fiber Bragg grating, long period grating and chirped grating were introduced into the OFSI, too. On the one hand, these methods are more or less complex and the special fibers used are not common employed.…”

Investigation of magneto-optical properties of magnetic fluid for fiber optics applications

“…The PMF-assisted polarimetric configuration is very simple, which can be potentially developed into an integrated fiber device. [118,120]; Special treatment processes like side polishing, chemical etching or tampering were applied to the fibers in the Sagnac loop to explore the potential [120,167]; Functional materials such as liquid crystal, alcohol and magnetic fluid were also used to enhance the sensitivity [73,117,121]. The large majority of these highly birefringent OFSI-based sensors share one thing in common that is only a partial length of the birefringent fiber within the Sagnac loop acted as the sensing element.…”

“…In the following Chapters, we will verify the these proposed MF-based optical fiber devices and try to improve their performance. to compare the sensitivities [118,120]; Special treating processes like side polishing, chemical etching or tampering were applied to the fiber in the Sagnac loop to explore the possibility [120]; Functional materials such as liquid crystal, alcohol and magnetic fluid were also used to enhance the sensitivity [73,117,121]. In this…”