Physical characteristics of localized surface plasmons resulting from nano-scale structured multi-layer thin films deposited on D-shaped optical fiber

Abstract

Novel surface plasmonic optical fiber sensors have been fabricated using multiple coatings deposited on a lapped section of a single mode fiber. UV laser irradiation processing with a phase mask produces a nano-scaled surface relief grating structure resembling nano-wires. The resulting individual corrugations produced by material compaction are approximately 20 μm long with an average width at half maximum of 100 nm and generate localized surface plasmons. Experimental data are presented that show changes in the spectral characteristics after UV processing, coupled with an overall increase in the sensitivity of the devices to surrounding refractive index. Evidence is presented that there is an optimum UV dosage (48 joules) over which no significant additional optical change is observed. The devices are characterized with regards to change in refractive index, where significantly high spectral sensitivities in the aqueous index regime are found, ranging up to 4000 nm/RIU for wavelength and 800 dB/RIU for intensity.

Curvature investigation in tapered fibers and its application to sensing and mode conversion

“…According to these experiments a sensitivity of 0.086 dB/μm is obtained for the strain sensor when using a continuous wave (CW) laser emitting in the maximum slope point of the fringe pattern and a power meter to build the sensor, which is competitive with state of art values [25,26]. Maximum sensitivities of 1000 dB/RIU are achieved when using this setup as RI sensor, which are competitive when compared to other refractive index sensing techniques as those shown in [27][28][29] which reported sensitivity values of 160 dB/RIU, 304.89 dB/RIU and 800 dB/RIU, respectively.…”

Detection of nitrous oxide using infrared optical plasmonics coupled with carbon nanotubes

“…The design and fabrication of the nitrous oxide sensing platform is a multi-stage process with the device's spectral behaviour characterised at each fabrication stage, the fact is that device's optical properties changes due to different optical mechanisms at the different stages. [28][29][30][31] The initial stage is the lapping of a standard telecoms optical bre (SMF28) that creates a D-shaped bre with the at area 3 microns from the core/cladding interface as shown in Fig. 1a, these lapped D-shaped bre are purchased from Phoenix Photonics Ltd, UK.…”

Micro and Nanostructured Materials for the Development of Optical Fibre Sensors

“…The materials employed to prepare the grid are transition metals such as platinum or gold (see Figure 28 ) [ 143 ]. To get a better sensitivity, the fibre can be D shaped and, onto the flat surface, layers of metals following a pattern are deposited: the pattern is obtained by using a laser beam through a mask [ 144 ]. The device is based on SPR induced by the metallic layers, and they are red shifted by the exposure to UV radiation.…”