NanoPlasmonics, Microphotonics & Imaging

As CMOS devices shrink in physical size, electrical interconnects between the devices will consume an ever-greater proportion of total chip power. A promising solution is to use silicon photonics for intra- and inter-chip communications. To be cost effective, both the optical transmitter and receiver should be made small, highly efficient, and CMOS compatible. Shrinking the photodiode will increase sensitivity and energy efficiency, but as it gets very small, the capacitance of the wire to the first amplifying stage in the receiver becomes significant. We present a solution which...

Silicon photonic switches have been developed for fast and low-cost optical switching. However most of demonstration is still limited in unicast operation. In this project, we develop a silicon photonic switch that is capable of multicast switching. We have implemented silicon photonic switches with movable waveguide couplers that can control power splitting ratio precisely. The switch has 4x20 ports, fast switching time (<9.6 us), low optical insertion loss (<4.0 dB), and small footprint (1.2 mm x 4.5 mm). We have demonstrated 1- to-2 and 1-to-4 multicast operation with the...

Amyloid beta (Aβ) is one of most crucial neuropathological biomarkers in Alzheimer's disease (AD). Up to date, the relation between the progress of the disorder and the interchange of Aβ level in the blood is still controversial; however, increasing evidence for transport of Aβ across the brain blood barrier (BBB) provides the linkage between concentrations of Aβ in central nervous system (CNS) and blood plasma. Hence, quantifying the Aβ level in blood plasma is considered as an emerging diagnostic method for AD. Here, we describe an integrated molecular diagnostic system (iMDx) for...

Controlling and concentrating infrared radiation has the potential to significantly impact infrared sensors, thermal imaging devices, as well as heat conversion systems. As most molecules have vibrational modes in the infrared range, they reradiate a great portion of the incident radiation instead of efficiently transmitting it. As a promising alternative, plasmonic gratings not only offer low-loss transmission of infrared radiation, but also compress the long infrared wavelengths. This localization effect greatly improves the sensing resolution and offers high-intensity fields at...