Optical Fiber Sensors Based on Polymeric Sensitive Coatings

Abstract

Abstract:Polymer technology is one of the fastest growing fields of contemporary research due to the possibility of using a wide variety of synthetic chemical routes for obtaining a polymeric network with a well-defined structure, resulting in materials with outstanding macroscopic properties. Surface engineering techniques based on the implementation of polymeric structures can be used as an interesting tool for the design of materials with functional properties. In this sense, the use of fabrication techniques for the design of nanostructured polymeric coatings is showing an important growth due to the intrinsic advantages of controlling the structure at a nanoscale level because physical, chemical, or optical properties can be considerably improved in comparison with the bulk materials. In addition, the presence of these sensitive polymeric coatings on optical fiber is a hot topic in the scientific community for its implementation in different market niches because a wide variety of parameters can be perfectly measured with a high selectivity, sensitivity, and fast response time. In this work, the two main roles that a polymeric sensitive matrix can play on an optical fiber for sensing applications are evaluated. In a first section, the polymers are used as a solid support for the immobilization of specific sensitive element, whereas in the second section the polymeric matrix is used as the chemical transducer itself. Additionally, potential applications of the optical fiber sensors in fields as diverse as biology, chemistry, engineering, environmental, industry or medicine will be presented in concordance with these two main roles of the polymeric sensitive matrices.

Layer-by-Layer Nano-assembly: A Powerful Tool for Optical Fiber Sensing Applications

“…The control of the structure of the coating at the nanoscale level allows the ability to tailor at the molecular level of the composition and structure of the sensitive coatings. The implementation of nanoscaled materials shows a special attraction because there are new phenomena observed when the matter is downscaled to this scale [41,42]. Consequently, research in nanostructured sensitive LbL coatings is a hot and challenging topic in the scientific community because these LbL sensitive nanocoatings can modify their optical properties as a function of the target parameter of analysis with an important enhancement in the response time, robustness, selectivity and sensitivity [43,44].…”

Long-Period Fiber Grating Sensor Based on a Conductive Polymer Functional Layer

“…In particular, close attention has been paid to long-period fiber gratings (LPFGs), particularly to the way in which light at the resonant wavelength of an LPFG is coupled from the guided to the cladding modes, which causes energy loss depending on the difference between the RI of the guided and cladding modes. For this reason, the previous study proposes a laser-assisted-etching LPFG (LLPFG) sensor fabricated using an excimer laser and metal photomasks, examines the effects of temperature on wavelength drift and transmission loss, and explores the use of LLPFG sensors for temperature sensing [ 1 , 2 ].…”

Optical Planar Waveguide Sensor with Integrated Digitally-Printed Light Coupling-in and Readout Elements

“…In this field, optical fiber sensors have reached a high degree of development. Coupling of light from lasers or light-emitting diodes (LEDs) is routinely performed currently by means of optical fiber couplers, and progress in sensing materials has enabled the implementation of sensors with improved sensitivity, portability, and reduced size [6,7].…”