Hydrogen Sensor Based on Palladium-Attached Fiber Bragg Grating

Enhancing Temperature Sensitivity Using Cyclic Polybutylene Terephthalate- (c-PBT-) Coated Fiber Bragg Grating

“…As such, research efforts have turned towards improving the performance of FBG-based temperature sensors by using temperature-sensitive materials as a coating to the FBG [18]. Among the techniques explored for this purpose include depositing or coating the FBG with metal or polymer layers [19][20][21][22], such as that reported by Chenari et al [23] which coated the FBG with polydimethylsiloxane (PDMS) layers of different cross-sectional areas. While significantly increasing the sensitivity of the FBG, this method required many preparatory steps including pretreating the FBG cladding surface with oxygen plasma, thus making this approach commercially impractical.…”

A PDMS-Coated Optical Fiber Bragg Grating Sensor for Enhancing Temperature Sensitivity

“…Ep and Ef are the Young's modulus values of the PDMS and the silica fiber, respectively. Equation (4) shows that the thermally induced length variation in our PDMScoated FBG structure can be expressed by the device dimension parameters and the material parameters of the thermal expansion coefficients. Considering the thermally induced refractive index variation in the silica fiber, the Bragg wavelength shift of the PDMS-coated FBG sensor according to temperature change can be written as follows.…”

“…In the past decades, fiber Bragg grating (FBG) sensors have been studied extensively for sensing several types of physical parameters such as temperature, strain, bending, and pressure [1][2][3][4][5][6] with optical methods. FBG sensors have the advantages of immunity to electromagnetic interference, compact structure, simple fabrication, and easy construction of long range monitoring system by using wavelengthmultiplexing schemes with cascaded FBGs.…”