49 research outputs found
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 mPEGâPCLâmPEG/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