Fully Reconfigurable Coupled-Resonator Optical Waveguides (CROWs) with 10 nW Static Power MEMS

We report on fully reconfigurable CROWs with MEMS-tunable waveguides. Resonator-to-resonator and resonator-to-waveguide coupling are fully tunable. Resonance of a resonator is also widely tunable to cover its full FSR. The static power consumption per tunable coupler is below 10nW. © OSA 2021, © 2021 The Author(s

8×8 Programmable Multi-Beam Pattern Projection Based on Multicast Silicon Photonic MEMS Switches

We present an arbitrary 8×8 beam pattern projection system based on a programmable grating coupler array with a Fourier lens. The static power consumption and the reconfiguration time are below 1W and 10s, respectively. © 2021 OSA

16-core recirculating programmable Si photonic MEMS

We report on a 16-core recirculating programmable photonic array based on MEMS-tunable directional couplers. The photonic array has a compact footprint (0.04mm2/cell) and negligible static power consumption. Waveguide-coupled single-ring resonators, CROWs, and add-drop filters are demonstrated. © OSA 2021, © 2021 The Author(s

Fully reconfigurable MEMS-based second-order coupled-resonator optical waveguide (CROW) with ultra-low tuning energy

Integrated microring resonators are well suited for wavelength-filtering applications in optical signal processing, and cascaded microring resonators allow flexible filter design in coupled-resonator optical waveguide (CROW) configurations. However, the implementation of high-order cascaded microring resonators with high extinction ratios (ERs) remains challenging owing to stringent fabrication requirements and the need for precise resonator tunability. We present a fully integrated on-chip second-order CROW filter using silicon photonic microelectromechanical systems (MEMS) to adjust tunable directional couplers and a phase shifter using nanoscale mechanical out-of-plane waveguide displacement. The filter can be fully reconfigured with regard to both the ER and center wavelength. We experimentally demonstrated an ER exceeding 25 dB and continuous wavelength tuning across the full free spectral range of 0.123 nm for single microring resonator, and showed reconfigurability in second-order CROW by tuning the ER and resonant wavelength. The tuning energy for an individual silicon photonic MEMS phase shifter or tunable coupler is less than 22 pJ with sub-microwatt static power consumption, which is far better than conventional integrated phase shifters based on other physical modulation mechanisms. © 2023 OSA - The Optical Society. All rights reserved.TRU

Three-dimensional nanopillar-array photovoltaics on low-cost and flexible substrates

Solar energy represents one of the most abundant and yet least harvested sources of renewable energy. In recent years, tremendous progress has been made in developing photovoltaics that can be potentially mass deployed1, 2, 3. Of particular interest to cost-effective solar cells is to use novel device structures and materials processing for enabling acceptable efficiencies4, 5, 6. In this regard, here, we report the direct growth of highly regular, single-crystalline nanopillar arrays of optically active semiconductors on aluminium substrates that are then configured as solar-cell modules. As an example, we demonstrate a photovoltaic structure that incorporates three-dimensional, single-crystalline n-CdS nanopillars, embedded in polycrystalline thin films of p-CdTe, to enable high absorption of light and efficient collection of the carriers. Through experiments and modelling, we demonstrate the potency of this approach for enabling highly versatile solar modules on both rigid and flexible substrates with enhanced carrier collection efficiency arising from the geometric configuration of the nanopillars