Temperature-Insensitive Bend Sensor Using Entirely Centered Erbium Doping in the Fiber Core

• Main Authors: Sulaiman Wadi Harun, Julian Md Samangun, Hairul Azhar Abdul-Rashid, Farah Diana Muhammad, Mohd Zamani Zulkifli, Harith Ahmad
• Format: Article
• Language: English
• Published: MDPI AG 2013-07-01
• Series: Sensors
• Subjects: bending sensor; special fiber; temperature-insensitivity; erbium-doped fiber
• Online Access: http://www.mdpi.com/1424-8220/13/7/9536

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.