Temperature-insensitive bend sensor using entirely centered Erbium doping in the fiber core

• Published in: Sensors (Basel, Switzerland) Switzerland), 2013-07, Vol.13 (7), p.9536-9546
• Main Authors: Ahmad, Harith, Zulkifli, Mohd Zamani, Muhammad, Farah Diana, Samangun, Julian Md, Abdul-Rashid, Hairul Azhar, Harun, Sulaiman Wadi
• Format: Article
• Language: English
• Subjects: bending sensor; Design; erbium-doped fiber; Sensors; special fiber; temperature-insensitivity
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s130709536

A fiber based bend sensor using a uniquely designed Bend-Sensitive Erbium Doped Fiber (BSEDF) is proposed and demonstrated. The BSEDF has two core regions, namely an undoped outer region with a diameter of about 9.38 μm encompassing a doped, inner core region with a diameter of 4.00 μm. The doped core region has about 400 ppm of an Er2O3 dopant. Pumping the BSEDF with a conventional 980 nm laser diode gives an Amplified Spontaneous Emission (ASE) spectrum spanning from 1,510 nm to over 1,560 nm at the output power level of about -58 dBm. The ASE spectrum has a peak power of -52 dBm at a central wavelength of 1,533 nm when not spooled. Spooling the BSEDF with diameters of 10 cm to 2 cm yields decreasing peak powers from -57.0 dBm to -61.8 dBm, while the central wavelength remains unchanged. The output is highly stable over time, with a low temperature sensitivity of around ~0.005 dBm/°C, thus allowing for the development of a highly stable sensor system based in the change of the peak power alone.