Simple temperature insensitive fiber Bragg grating based tilt sensor with enhanced tunability

Abstract

A design for an all-optical temperature insensitive fiber Bragg grating (FBG) based tilt sensor is reported. The sensor is capable of measuring the magnitude as well as the direction of inclination from the horizontal with a complete reversible response over the designed dynamic range of AE45°. The most important feature of the reported sensor is its inherent enhanced tuning capability for its sensitivity. An excellent sensitivity of the order of ∼0:0626 nm=°that can further be tuned is observed for the sensor. Experimental results show that a tilt angle resolution better than 0:008°with a tilt accuracy of ∼ AE 0:36°w as achieved.

Very sensitive fiber Bragg grating accelerometer using transverse forces with an easy over-range protection and low cross axial sensitivity

“…FBG is inherently sensitive to strain and temperature. Modulating its strain can measure acceleration [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], strain and displacement [18,19], inclination [20,21], temperature [22,23], and so on. We demonstrated that its strain is more sensitive to transverse forces than axial forces [24].…”

Interferometric Fiber-Optic Tilt Sensor Exploiting Taper and Lateral-Offset Fusing Splicing

“…For the tilt ranging from 0 to -5 deg, the wavelength shift linearly decreases with the increment of the tilt, on the contrary, the wavelength shift linearly increases with the increment of the tilt. No matter the sensor is operated in the - or the + directions, the wavelength shift sensitivity of this kind of the proposed fiber interferometric-based sensors reaches up to 1.15nm/deg with good repeatability, which is far higher than those of the grating-based tilt sensors in [3][4][5][6][7][8][9][10] and several times higher than those of the fiber interferometric-based sensors in [11,13]. The high sensitivity should be associated with the interference pattern between the higher-order cladding mode and the core mode, which is in accordance with the theoretical analysis in part two.…”

“…Among them, fiber grating based tilt sensors with different configurations are the most popular apparatus. Examples include vertical-pendulum-based fiber Bragg grating (FBG) tilt sensors [3][4], temperature-insensitive 2-D tilt sensors based on FBGs [5][6][7], tilt sensor based on long period fiber grating (LPFG) [8][9], and wide-range tilt sensor based on weakly tilted fiber Bragg grating (TFBG) [10]. These devices have recognized reliability and favorable sensing characteristics, but the large sensing integration and complicated fabrication process degrade their practical applications.…”

A Highly Sensitive Two-Dimensional Inclinometer Based on Two Etched Chirped-Fiber-Grating Arrays

“…Among these methods, optical fiber grating based sensors have been found ideal in many applications due to their intrinsic advantages of small size, high sensitivity, long-term stability multiplexing capability, and immunity to electromagnetic interference (EMI), which make them suitable in field-deployed monitoring [1,2]. In recent years, several fiber Bragg grating (FBG)-based inclinometer or tilt sensors with different configurations for one or two-dimension (1-D or 2-D) measurements have been reported [3,4,5,6,7,8,9,10,11,12,13,14,15]. For example, Dong et al have proposed a design based on three FBGs.…”

“…There are many FBG based temperature-insensitive tilt sensors or inclinometers [7,8,9,10,11,14]. However, these sensors are either large in size or lack high sensitivity.…”