Sino-German College of Intelligent Manufacturing
Physical Sensing
Enhancement of the sensitivity of magneto-optical fiber sensor by magnifying the birefringence of magnetic fluid film with Loyt-Sagnac interferometer
Peng Zu, Chi Chiu Chan, Guo Wei Koh, Wen Siang Lew, Yongxing Jin, Hwi Fen Liew, Wei Chang Wong, Xinyong Dong
Published in Sensors and Actuators B-Chemical
Abstract
Magnetic field sensor by combing magnetic fluid and optical fiber Loyt-Sagnac interferometer is proposed. The sensor takes advantage of the birefringence effect of magnetic fluid. The relative small birefringence of the magnetic fluid is ‘magnified�by the properly designed optical fiber Loyt-Sagnac interferometric structure. As compared to the reported MF-based sensors, the achieved sensitivity of the proposed sensor is 592.8 pm/Oe, which is enhanced by 1� orders of magnitude.
Fiber Bragg grating-based load sensor without temperature dependence
Limin Hu, Xinyong Dong, Shuqin Zhang, Shangzhong Jin, Yunpeng Wang, Chi Chiu Chan, and Ping Shum
Published in Microwave and Optical Technology Letters
Abstract
A novel load sensor has been proposed and demonstrated by embedding a fiber Bragg grating (FBG) into a tapered cylindrical polymer rod. Load-induced nonuniform strain field changes the bandwidth, and hence, the reflected optical power of the FBG. Temperature-insensitive measurement of load has been realized by measuring the reflected optical power with only a low-cost optical power meter. Load measurement sensitivity of 5.0 nW/N has been experimentally achieved within a range up to 1800 N.
Tilted Long Period Gratings Pressure Sensing in Solid Core Photonic Crystal Fibers
Yi Fan Zhang, Chi Chiu Chan, Yen Mei Chan, and Peng Zu
Published in IEEE Sensors Journal
Abstract
A photonic crystal fiber pressure sensor using mechanical induced tilted long period grating is reported. Trans- mission dip has a blue shift when the tilted angle of the long period grating increases. The performances of the pressure sensor are evaluated by the shifting of the transmission spectrum after applying different pressure level. The experimental results show that the larger the tilted angle of the grating, the transmission dip experiences the larger blue-shift, leading to higher sensitivity up to 2.701 nm/MPa.
Magneto-optical fiber sensor based on bandgap effect of photonic crystal fiber infiltrated with magnetic fluid
Peng Zu, Chi Chiu Chan, Tianxun Gong, Yongxing Jin, Wei Chang Wong, and Xinyong Dong
Published in Applied Physics Letters
Abstract
A magnetic field sensor based on combination of the magnetic fluid and the tunable photonic bandgap effect of photonic crystal fiber is proposed. The magnetic fluid with higher refractive index (>1.45) is prepared and filled into the air-holes of photonic crystal fiber to convert the index guiding fiber into photonic bandgap fiber. The proposed sensor takes full advantage of the ultrahigh sensitivity characteristic of photonic bandgap fiber and achieves a high sensitivity and resolution of 1.56 nm/Oe and 0.0064 Oe, respectively, which are 2-3 orders of magnitude better than other sensors based on magnetic fluid.