In this work, a novel technique to create adaptive liquid crystal lenses and other optical components is proposed and demonstrated. This proposal avoid all of the previous techniques disadvantages, a simple fabrication process and low voltage control is required, and thin lenses can be obtained. The novelty of the proposal, resides in a micro-structured indium tin oxide, designed to transmit the voltage homogeneously across the entire surface of the active area. This design is composed of two main elements, a transmission line that generates a voltage gradient, and a series of combs that distribute the voltage across the entire active area. Two different apertures are designed. One of this designs is fabricated and measured to demonstrate the viability of the idea. This novel structure open new venues of research in phase-only LC optical devices.
In this work, a novel method to obtain all-dielectric toroidal response metasurfaces in the W-band and THz range is demonstrated. Two designs are proposed, a symmetric and asymmetric disk metasurface. The first design is intended to corroborate the theoretical analysis, demonstrating the excitation of a strong toroidal mode resonance at 93.2 GHz. Then, the second design is used to demonstrate that symmetry-breaking variations in the disk dimensions, could lead to birefringent metasurfaces, affecting the polarization of the impinging light. Two structures are designed, a polarization beam splitter and a polarization converter. Such devices are difficult to obtain at the target frequency range with low absorption, so they could be of particular interest for the next generation of 5G communications and THz devices.
A localized surface plasmon resonance based fiber optic sensor for temperature sensing has been analyzed theoretically. The effects of the size of the spherical metal nanoparticle on the performance of the sensor have been studied in detail. The high sensitivity of localized surface plasmon resonances to refraction index changes, in collaboration with the high thermo-optic coefficients of Liquid Crystal materials, has result in a fiber optical sensor with high temperature sensitivity. This sensitivity has been demonstrated to be dependent on nanoparticle size. Maximum sensitivities of 4nm/°C can be obtained for some specific temperature ranges. The proposed sensor will be low cost, and will have all the typical advantages of fiber optic sensors.