We report the design, fabrication, and demonstration of antiresonant reflecting optical (ARROW) waveguides with hollow cores. We describe the design principles to achieve low waveguide loss in both transverse and lateral directions. A novel fabrication process using silicon dioxide and silicon nitride layers as well as sacrificial polyimide core layers was developed. Optical characterization of 3.5µm thick waveguides with air cores was carried out. We demonstrate single-mode propagation through these hollow ARROW waveguides with propagation loss as low as 6.5cm^-1 and mode cross sections down to 6.7µm². Applications of these waveguides to sensing and quantum communication are discussed.

The control of magnetism by acoustically induced strain has driven significant research activities, with the ultimate goal of pursuing novel, ultrafast, compact, and energy-efficient electronic and spintronic applications. Here, we aim to present for the first time a comprehensive review of this field, which has seen a surge of interest in recent years. We review fundamental understanding of magnetoelastic coupling phenomena and mechanisms, diverse experimental configurations, recent advances in modeling and microscopic tools to intuitively describe them, and the experimental and theoretical exploration of devices and technological innovations. These include acoustic spintronics, surface acoustic wave (SAW)-assisted spin transfer torque (STT) switching, SAW-assisted all-optical switching (AOS), SAW-driven spin textures (e.g., Skyrmions and domain walls), acoustic Terahertz emitters, SAW magnetic field sensors, magnetoelastic antenna, on-demand magnonic crystals, and so on. Focusing on the translation of many fundamental research breakthroughs into potential technological applications, we identify the key challenges and opportunities in the field, which we hope may motivate further research efforts of moving scientific discoveries toward real applications.

The massive outbreak of highly lethal Ebola hemorrhagic fever in West Africa illustrates the urgent need for diagnostic instruments that can identify and quantify infections rapidly, accurately, and with low complexity. Here, we report on-chip sample preparation, amplification-free detection and quantification of Ebola virus on clinical samples using hybrid optofluidic integration. Sample preparation and target preconcentration are implemented on a PDMS-based microfluidic chip (automaton), followed by single nucleic acid fluorescence detection in liquid-core optical waveguides on a silicon chip in under ten minutes. We demonstrate excellent specificity, a limit of detection of 0.2 pfu/mL and a dynamic range of thirteen orders of magnitude, far outperforming other amplification-free methods. This chip-scale approach and reduced complexity compared to gold standard RT-PCR methods is ideal for portable instruments that can provide immediate diagnosis and continued monitoring of infectious diseases at the point-of-care.

We present a fully planar integrated optofluidic platform that permits single particle detection, manipulation and analysis on a chip. Liquid-core optical waveguides guide both light and fluids in the same volume. They are integrated with fluidic reservoirs and solid-core optical waveguides to define sub-picoliter excitation volumes and collect the optical signal, resulting in fully planar beam geometries. Single fluorescently labeled liposomes are used to demonstrate the capabilities of the optofluidic chip. Liposome motion is controlled electrically, and fluorescence correlation spectroscopy (FCS) is used to determine concentration and dynamic properties such as diffusion coefficient and velocity. This demonstration of fully planar particle analysis on a semiconductor chip may lead to a new class of planar optofluidics-based instruments.