Publications

A novel low-profile nonlinear metasurface, consisting of a single-layer of all-dielectric material, is proposed and numerically investigated by a nonlinear full-wave finite-difference time-domain (FDTD) method. The proposed metasurface is transparent for low, and opaque for high values of incident light intensity. The metasurface design is broadly applicable to enhancement of...

Diffractive waveplates and equivalent metasurfaces provide a promising path for applications in thin film beam steering, tunable lenses, and polarization filters. However, fixed metasurfaces alone are unable to be tuned electronically. By combining metasurfaces with tunable liquid crystals, we experimentally demonstrate a single layer device capable of electrically switching a...

Controlling and optimising the alignment of liquid crystals is a crucial process for display application. Here, we investigate the effects of humidity and surface types on photoalignment of an azo-dye brilliant yellow (BY). Specifically, the effect of humidity on the photoalignment of BY was studied at the stage of substrate...

In this paper, we examine a laser-based approach to remotely initiate, measure, and differentiate acoustic and vibrational emissions from trace quantities of explosive materials against their environment. Using a pulsed ultraviolet laser (266 nm), we induce a significant (>100  Pa) photoacoustic response from small quantities of military-grade explosives. The photoacoustic signal...

An uncooled thermal imager is being developed based on a liquid crystal (LC) transducer. Without any electrical connections, the LC transducer pixels change the long-wavelength infrared (LWIR) scene directly into a visible image as opposed to an electric signal in microbolometers. The objectives are to develop an imager technology scalable...

This work demonstrates a novel broadband optical switch, based on dynamic-scattering effect in liquid crystals (LCs). Dynamic-scattering-mode technology was developed for display applications over four decades ago, but was displaced in favor of the twisted-nematic LCs. However, with the recent development of more stable LCs, dynamic scattering provides advantages over...

A novel sensor is being developed for a new uncooled imager technology that is scalable to large formats (tens of megapixels), which is greater than what is achieved by commercial microbolometer arrays. In this novel sensor, a liquid-crystal transducer is used to change a long-wavelength infrared scene into a visible...

Direct-write printing allows the fabrication of centimeter-wave radio devices. Most polymer dielectric polymer materials become lossy at frequencies above 10 GHz. Presented here is a printable dielectric material with low loss in the K a band (26.5–40 GHz). This process allows the fabrication of resonator filter devices and a radio...

Spectroscopic ellipsometry is demonstrated to be an effective technique for assessing the quality of plasmonic resonances within aluminum nanostructures deposited with multiple techniques. The resonance quality of nanoplasmonic aluminum arrays is shown to be strongly dependent on the method of aluminum deposition. Three-layer metal-dielectric-metal nanopillar arrays were fabricated in a...

The conversion of electrical to mechanical power on a sub-centimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper, we present a type of a capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These...