Simultaneous measurement of temperature and strain of a fixed composite cantilever using a π-PSFBG sensor

Air Gap Fiber Bragg Grating for Simultaneous Strain and Temperature Measurement

“…Like FPI, PSFBG exhibits a linear relationship between the wavelength shift of its reflection spectrum and the variations in strain (Δ ε ) and temperature (Δ T ). The wavelength shift Δ λ PSFBG of its dip can be described by the following formula [ 22 ]: where K PSFBG ε and K PSFBG T are the strain and temperature sensitivities of PSFBG, respectively.…”

“…chirped long-period grating [14], superstructure FBG [15], misaligning splicing a thin core fiber between two SMFs [16], combining few-mode fiber and FBG [17,18], combining FBG and multimode fiber [19], tilted FBG [20], specially packaged FBG [21], π-phase-shifted FBG [22], and a combination of different types of interferometers and FBG [23][24][25][26]. However, there are some flaws such as relatively high complexity, difficult fabrication process, or low sensitivity in some of those approaches, which restrict their practical applications.…”

“…Dan Su et al [ 9 ] proposed a measurement scheme for dual-parameter measurements using a double-fiber grating written by a single-mode fiber and a thin-core fiber. Furthermore, there are several other approaches such as polarization-maintaining few-mode Bragg gratings [ 10 ], sawtooth stressor-assisted highly birefringent FBG [ 11 ], cascaded long-period fiber grating or Bragg grating [ 12 , 13 ], multimode fiber chirped long-period grating [ 14 ], superstructure FBG [ 15 ], misaligning splicing a thin core fiber between two SMFs [ 16 ], combining few-mode fiber and FBG [ 17 , 18 ], combining FBG and multimode fiber [ 19 ], tilted FBG [ 20 ], specially packaged FBG [ 21 ], π-phase-shifted FBG [ 22 ], and a combination of different types of interferometers and FBG [ 23 , 24 , 25 , 26 ]. However, there are some flaws such as relatively high complexity, difficult fabrication process, or low sensitivity in some of those approaches, which restrict their practical applications.…”

“…tilted FBG [20], specially packaged FBG [21], π-phase-shifted FBG [22], and a combination of different types of interferometers and FBG [23][24][25][26]. However, there are some flaws such as relatively high complexity, difficult fabrication process, or low sensitivity in some of those approaches, which restrict their practical applications.…”

Effects of Curvature on Flexible Bragg Grating in Off-Axis Core: Theory and Experiment

“…In particular, the development of flexible photonic structures and devices using ultrathin glasses, which are mechanically flexible, has provided a new opportunity in addition to the use of polymer-based materials [11]. Optical sensors are suitable for curvature measurements because of their key features such as light weight, dimensions, electromagnetic interference immunity, harsh environments operability, nontoxic, and high sensitivity [1], [12], [13]. The maximum curvature depends on the thickness of the glass and the presence of surface defects, which are related to the fabrication process [9].…”