Temperature Sensor Based on Side-Polished Fiber SPR Device Coated with Polymer

Abstract

A highly sensitive temperature sensor based on surface plasmon resonance (SPR) of a side-polished single mode fiber is demonstrated. The sensor consists of a gold film coated side-polished fiber covered by a layer of UV-curable adhesive. Before introducing the UV-curable adhesive, the gold-coated fiber exhibits refractive index (RI) sensitivity of 1691.6 nm/RIU to 8800 nm/RIU in the range of 1.32 to 1.43. The resonant wavelength of the SPR sensor shifts to 650 nm when the adhesive is coated on the gold film, and is fixed at about 725 nm when the adhesive is cured. Due to the high thermo-optic and thermal expansion coefficient of the adhesive, the sensor structure achieves a temperature sensitivity of −0.978 nm/°C between 25 °C and 100 °C. The proposed optical fiber SPR sensor is simple, highly sensitive and cost effective, which may find potential applications for temperature measurements in the biomedical and environmental industries.

A Review of Coating Materials Used to Improve the Performance of Optical Fiber Sensors

“…The combination of UV-curable adhesive and SPR is indispensable in many kinds of sensors. In [ 94 ] and Figure 22 , an SPR sensor was proposed based on SMF, UV-curable adhesive, and gold film. The whole sensing area was completely enclosed by UV-curable adhesive, which enhanced the sensing function while protecting the fiber structure.…”

“…Compared with other materials, the fabrication of coating UV-curable polymer on the fiber is relatively simple, because UV-curable polymer has the characteristic of curing when exposed to UV light [88][89][90][91][92][93][94]. In the absence of UV light at room temperature, UV-curable polymer can maintain the state of the liquid for a long time, which makes it possible to manipulate it on sensors.…”

“…In [100], the cladding of SMF was removed, the graphene oxide encapsulated gold nanoparticle was coated on the core, and a novel cladding was made [100]. A structure that was similar to that in [28,94] was mentioned again, except that the coated material became graphene. Without exception, such sensors are also structurally weak.…”

Plasmonic Layer as a Localized Temperature Control Element for Surface Plasmonic Resonance-Based Sensors

“…The sensor is, thus, converted into a biosensor that will convert any biomolecular event arising at sensor surface into an optical refractive index variation. However, whatever the medium at sensor surface is, its optical refractive index will depend on the temperature, which, thus, modifies the measurement [ 15 ]; SPR has then understandably been investigated as an optical temperature sensing technique [ 16 , 17 ]. Consequently, any of the smallest temperature alteration can be interpreted as a molecular interaction, and thus, give a false biosensing result.…”

The Response of UV/Blue Light and Ozone Sensing Using Ag-TiO2 Planar Nanocomposite Thin Film

“…Different metal nanoparticles (Ag, Au) doped on MOSs are widely used in many fields to generate SPR and enhance photocatalysis; they are also used in gas sensors, environmental protection technologies, solar cells, energy storage devices, and photoelectric materials [17,18,19]. For example, researchers have applied SPR with magnetic microspheres for prion protein detection [20,21,22], a magnetic biochip (Au/Fe 2 O 3 /Au) for antigen detection [23], core-shell γ -Fe2O3@Au nanoparticles for low-field nuclear magnetic resonance [24], a gold film-coated side-polished fiber for temperature sensor fabrication [25], and Au@SiO 2 core-shell NPs into TiO 2 scaffold layer to increase the power conversion efficiency of solar cells [26].…”