This paper demonstrates the feasibility of multiplexing several optical fibre-based Fabry-Perot sensors in series for strain metrology. White-light interferometry was employed using the laser-referenced Michelson interferometer of a standard Fourier-transform spectrometer as a receiving (interrogating) interferometer. The primary aim was to demonstrate that at least six fibre Fabry-Perot transducer interferometers (sensors) can be multiplexed in series. A prerequisite for this sensor system is that each sensor has to have a unique optical cavity length within the multiplex. The resulting differing optical path differences at each fibre Fabry-Perot sensor give rise to sharp correlation features (side bursts) at unique positions in the time domain as observed in the interferogram. An optical cavity length change due to an axial strain perturbation is observed as a change in the position in the time domain of the side-burst feature associated with the optical fibre Fabry-Perot sensor. This paper demonstrates that multiplexed strain metrology in the quasi-static regime using optical fibre Fabry-Perot sensors is possible with a measurement range of typically 0-4000 microstrain and a strain resolution of better than 10 microstrain.

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Metal oxide nanostructure hybrid materials have garnered focused attention for next-generation memory-based devices. TiO 2 nanostructure hybrids dwell in that league of materials. In reference to that, the present work reports the growth of mixed-phase TiO 2 nanostructures (MxPh-TNs) and their hybrids by grafting metal nanoparticles (MNPs). MxPh-TNs are a concoction of rutile nanorods and anatase nanotubes, imaged using field-emission scanning electron microscope and further confirmed by micro-Raman spectroscopy. During the growth of MxPh-TNs, a rutile and anatase mixed-phase interface is formed, as confirmed by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Furthermore, by grafting MNPs of platinum (Pt) and palladium−platinum (Pd−Pt) over MxPh-TNs, a top interface is investigated in order to have modifications in their structure and electronic interaction. Thus, dual interfaces corresponding to a mixed phase (rutile and anatase) and MNPs/TNs result in the modification of formed nanostructures and their hybrids (MX-TNHs), as confirmed by X-ray photoelectron spectroscopy and Kelvin probe force microscopy (KPFM) studies. Modification at the interface results in improved crystallinity and symmetric barriers for charge transport in hybrid structures. MxPh-TNs and MX-TNHs are further explored for device applications in the form of memristive resistive switching devices. It is observed that the device performances of Pt/MX-TNHs and Pd−Pt/MX-TNHs are better than that of MxPh-TNs in terms of the memory window (I ON /I OFF ratio). The improved device performance in the hybrid structures are due to the enhanced charge separation and defects at the interface of MNPs (Pt and Pd−Pt) and MxPh-TNs.

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