Abstract
A compact and low-power consuming fiber-optic anemometer based on single-walled carbon nanotubes (SWCNTs) coated tilted fiber Bragg grating (TFBG) is presented. TFBG as a near infrared in-fiber sensing element is able to excite a number of cladding modes and radiation modes in the fiber and effectively couple light in the core to interact with the fiber surrounding mediums. It is an ideal in-fiber device used in a fiber hot-wire anemometer (HWA) as both coupling and sensing elements to simplify the sensing head structure. The fabricated TFBG was immobilized with an SWCNT film on the fiber surface. SWCNTs, a kind of innovative nanomaterial, were utilized as light-heat conversion medium instead of traditional metallic materials, due to its excellent infrared light absorption ability and competitive thermal conductivity. When the SWCNT film strongly absorbs the light in the fiber, the sensor head can be heated and form a “hot wire”. As the sensor is put into wind field, the wind will take away the heat on the sensor resulting in a temperature variation that is then accurately measured by the TFBG. Benefited from the high coupling and absorption efficiency, the heating and sensing light source was shared with only one broadband light source (BBS) without any extra pumping laser complicating the system. This not only significantly reduces power consumption, but also simplifies the whole sensing system with lower cost. In experiments, the key parameters of the sensor, such as the film thickness and the inherent angle of the TFBG, were fully investigated. It was demonstrated that, under a very low BBS input power of 9.87 mW, a 0.100 nm wavelength response can still be detected as the wind speed changed from 0 to 2 m/s. In addition, the sensitivity was found to be −0.0346 nm/(m/s) under the wind speed of 1 m/s. The proposed simple and low-power-consumption wind speed sensing system exhibits promising potential for future long-term remote monitoring and on-chip sensing in practical applications.
Highlights
Fiber-optic sensors have become attractive candidates for various kinds of measurements, such as temperature, axial strain, and acoustic emission, due to their distinguished advantages of small size, high accuracy, anti-electromagnetic interference, long-term stability, and multiplexing capability [1,2,3,4,5]
Wang et al proposed an interesting low-power-consumption fiber-optic anemometer based on a metal-filled microstructured optical fiber (MOF) and fiber Bragg grating (FBG) [20]
A novel fiber wind speed sensor with a compact size and low power consumption is proposed, which is based on single-walled carbon nanotubes (SWCNTs) coated titled fiber Bragg grating (TFBG)
Summary
Fiber-optic sensors have become attractive candidates for various kinds of measurements, such as temperature, axial strain, and acoustic emission, due to their distinguished advantages of small size, high accuracy, anti-electromagnetic interference, long-term stability, and multiplexing capability [1,2,3,4,5]. Caldas et al proposed a fiber-optic hot-wire flowmeter based on a metallic coated hybrid long period fiber Bragg grating (LPG) structure [18] They used an LPG to couple laser light in the core to interact with the Ag film coated near the LPG region, and another FBG was inscribed under the coating to measure the temperature variation. This design avoided the geometry modification of the fiber, the sensing structure was still complicated and showed low light-heat conversion efficiency. A novel fiber wind speed sensor with a compact size and low power consumption is proposed, which is based on single-walled carbon nanotubes (SWCNTs) coated titled fiber Bragg grating (TFBG). The proposed simple and low-power-consumption anemometer system exhibits promising potentials for future long-term remote sensing in practical applications
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
