Photonic Interferometric Imager with monolithic silicon CMOS photonic integrated circuits

We demonstrate, for the first time to our knowledge, a monolithically-integrated photonic interferometric imager circuit with on-chip detectors, CMOS trans-impedance-amplifiers, and associated photonic imager components. A proof-of-principle demonstration of interferogram fringe generation will be discussed

Demonstration of Programmable Brain-Inspired Optoelectronic Neuron in Photonic Spiking Neural Network with Neural Heterogeneity

Photonic Spiking Neural Networks (PSNN) composed of the co-integrated CMOS and photonic elements can offer low loss, low power, highly-parallel, and high-throughput computing for brain-inspired neuromorphic systems. In addition, heterogeneity of neuron dynamics can also bring greater diversity and expressivity to brain-inspired networks, potentially allowing for the implementation of complex functions with fewer neurons. In this paper, we design, fabricate, and experimentally demonstrate an optoelectronic spiking neuron that can simultaneously achieve high programmability for heterogeneous biological neural networks and maintain high-speed computing. We demonstrate that our neuron can be programmed to tune four essential parameters of neuron dynamics under 1GSpike/s input spiking pattern signals. A single neuron circuit can be tuned to output three spiking patterns, including chattering behaviors. The PSNN consisting of the optoelectronic spiking neuron and a Mach-Zehnder interferometer (MZI) mesh synaptic network achieves 89.3% accuracy on the Iris dataset. Our neuron power consumption is 1.18 pJ/spike output, mainly limited by the power efficiency of the vertical-cavity-lasers, optical coupling efficiency, and the 45 nm CMOS platform used in this experiment, and is predicted to achieve 36.84 fJ/spike output with a 7 nm CMOS platform (e.g. ASAP7) integrated with silicon photonics containing on-chip micron-scale lasers

A hybrid platform for three-dimensional printing of bone scaffold by combining thermal-extrusion and electrospinning methods

Published: 05 February 2020The aim of this study is to develop a hybrid 3D printing platform integrating thermal-extrusion and electrospinning methods to fabricate bone scaffolds. The scaffolds made by mPEG–PCL–mPEG/HA biocomposite and their surface were enhanced by adding an electrospun fibre layer which improved adhesion and viability of osteoblastic cells. The scaffolds were evaluated by mechanical testing; biochemical analyses, SEM observation and their capabilities for supporting growth and adhesion of osteoblastic cells were also assessed in vitro. The 3D printing platform can manufacture the controllable and complicated shapes of bone scaffolds by controlling the thermal-extrusion and electrospinning equipment. It also can control the pore size, porosity and pore interconnectivity, and stack the scaffold structure by using different materials and different ways. Analyses showed that the bone scaffolds have a good mechanical strength and the scaffolds are suitable to support growth of MC3T3-E1 osteoblastic cells; and the electrospun fibres may increase the surface area of the fabricated scaffolds for the future application in modulating osteoblast response. Thus, it is feasible to produce bone tissue engineering scaffolds integrating thermal-extrusion and electrospinning techniques using our 3D printing platform.Jianghui Dong, Ru-Jhang Jhu, Liping Wang, Cho-Pei Jiang and Cory J. Xia

Protocols for dynamically probing topological edge states and dimerization with fermionic atoms in optical potentials

Topological behavior has been observed in quantum systems including ultracold atoms. However, background harmonic traps for cold-atoms hinder direct detection of topological edge states arising at the boundary because the distortion fuses the edge states into the bulk. We propose experimentally feasible protocols to probe localized edge states and dimerization of ultracold fermions. By confining cold-atoms in a ring lattice and changing the boundary condition from periodic to open using an off-resonant laser sheet to cut open the ring, topological edge states can be generated. A lattice in a topological configuration can trap a single particle released at the edge as the system evolves in time. Alternatively, depleting an initially filled lattice away from the boundary reveals the occupied edge states. Signatures of dimerization in the presence of contact interactions can be found in selected correlations as the system boundary suddenly changes from periodic to open and exhibit memory effects of the initial state distinguishing different configurations or phases.Comment: 6 pages, 3 figure