954 research outputs found
Graphene/silicon heterojunction for reconfigurable phase-relevant activation function in coherent optical neural networks
Optical neural networks (ONNs) herald a new era in information and
communication technologies and have implemented various intelligent
applications. In an ONN, the activation function (AF) is a crucial component
determining the network performances and on-chip AF devices are still in
development. Here, we first demonstrate on-chip reconfigurable AF devices with
phase activation fulfilled by dual-functional graphene/silicon (Gra/Si)
heterojunctions. With optical modulation and detection in one device, time
delays are shorter, energy consumption is lower, reconfigurability is higher
and the device footprint is smaller than other on-chip AF strategies. The
experimental modulation voltage (power) of our Gra/Si heterojunction achieves
as low as 1 V (0.5 mW), superior to many pure silicon counterparts. In the
photodetection aspect, a high responsivity of over 200 mA/W is realized.
Special nonlinear functions generated are fed into a complex-valued ONN to
challenge handwritten letters and image recognition tasks, showing improved
accuracy and potential of high-efficient, all-component-integration on-chip
ONN. Our results offer new insights for on-chip ONN devices and pave the way to
high-performance integrated optoelectronic computing circuits
Programmable photonics : an opportunity for an accessible large-volume PIC ecosystem
We look at the opportunities presented by the new concepts of generic programmable photonic integrated circuits (PIC) to deploy photonics on a larger scale. Programmable PICs consist of waveguide meshes of tunable couplers and phase shifters that can be reconfigured in software to define diverse functions and arbitrary connectivity between the input and output ports. Off-the-shelf programmable PICs can dramatically shorten the development time and deployment costs of new photonic products, as they bypass the design-fabrication cycle of a custom PIC. These chips, which actually consist of an entire technology stack of photonics, electronics packaging and software, can potentially be manufactured cheaper and in larger volumes than application-specific PICs. We look into the technology requirements of these generic programmable PICs and discuss the economy of scale. Finally, we make a qualitative analysis of the possible application spaces where generic programmable PICs can play an enabling role, especially to companies who do not have an in-depth background in PIC technology
Principles of Neuromorphic Photonics
In an age overrun with information, the ability to process reams of data has
become crucial. The demand for data will continue to grow as smart gadgets
multiply and become increasingly integrated into our daily lives.
Next-generation industries in artificial intelligence services and
high-performance computing are so far supported by microelectronic platforms.
These data-intensive enterprises rely on continual improvements in hardware.
Their prospects are running up against a stark reality: conventional
one-size-fits-all solutions offered by digital electronics can no longer
satisfy this need, as Moore's law (exponential hardware scaling),
interconnection density, and the von Neumann architecture reach their limits.
With its superior speed and reconfigurability, analog photonics can provide
some relief to these problems; however, complex applications of analog
photonics have remained largely unexplored due to the absence of a robust
photonic integration industry. Recently, the landscape for
commercially-manufacturable photonic chips has been changing rapidly and now
promises to achieve economies of scale previously enjoyed solely by
microelectronics.
The scientific community has set out to build bridges between the domains of
photonic device physics and neural networks, giving rise to the field of
\emph{neuromorphic photonics}. This article reviews the recent progress in
integrated neuromorphic photonics. We provide an overview of neuromorphic
computing, discuss the associated technology (microelectronic and photonic)
platforms and compare their metric performance. We discuss photonic neural
network approaches and challenges for integrated neuromorphic photonic
processors while providing an in-depth description of photonic neurons and a
candidate interconnection architecture. We conclude with a future outlook of
neuro-inspired photonic processing.Comment: 28 pages, 19 figure
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