A5036567766- Neural Networks and Reservoir Computing
- Advanced Memory and Neural Computing
- Photonic and Optical Devices
- Neural dynamics and brain function
- Semiconductor Lasers and Optical Devices
- Semiconductor Quantum Structures and Devices
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Advanced Antenna and Metasurface Technologies
- Metamaterials and Metasurfaces Applications
- Photoreceptor and optogenetics research
- Microwave Engineering and Waveguides
- Phase-change materials and chalcogenides
- Antenna Design and Analysis
University of Glasgow
2021-2024
This work provides a first report of ultrafast and compact photonic-electronic neuromorphic temporal leaky integrate-and-fire neuronal circuits built with Resonant Tunnelling Diodes (RTDs). We demonstrate experimentally that multiple fast (~100-200 ps) optical input pulses, arriving within short (sub-ns long) window, control the triggering excitable responses in two different RTD circuit architectures. These architectures are an electronic coupled externally to photodetector (referred as...
Abstract Nanophotonic spiking neural networks (SNNs) based on neuron-like excitable subwavelength (submicrometre) devices are of key importance for realizing brain-inspired, power-efficient artificial intelligence (AI) systems with high degree parallelism and energy efficiency. Despite significant advances in neuromorphic photonics, compact efficient nanophotonic elements signal emission detection, as required spike-based computation, remain largely unexplored. In this invited perspective,...
Excitable optoelectronic devices represent one of the key building blocks for implementation artificial spiking neurons in neuromorphic (brain-inspired) photonic systems. This work introduces and experimentally investigates an opto-electro-optical (O/E/O) neuron built with a resonant tunnelling diode (RTD) coupled to photodetector as receiver vertical cavity surface emitting laser transmitter. We demonstrate well-defined excitability threshold, above which produces optical responses...
Abstract This work reports a nanostructure resonant tunnelling diode-photodetector (RTD-PD) device and demonstrates its operation as controllable, optically-triggered excitable spike generator. The top contact layer of the is designed with nanopillar structure (500 nm in diameter) to restrain injection current, yielding therefore lower energy for generation. We demonstrate experimentally deterministic optical triggering controllable repeatable neuron-like patterns RTD-PDs. Moreover, we show...
Abstract Optoelectronic artificial spiking neurons are regarded as promising core elements for novel photonic neuromorphic computing hardware. In this work, we investigate a modular optoelectronic neuron built with an excitable resonant tunneling diode (RTD) coupled to photodetector and vertical-cavity surface-emitting laser (VCSEL). This work provides the first experimental demonstration of amplitude control fired optical spikes in electrical-to-optical part neuron, therefore introducing...
We investigate the dynamic behaviour of resonant tunneling diode-photodetectors (RTD-PDs) in which excitability can be activated by either electrical noise or optical signals. In both cases, we find characteristics stochastic spiking behavior are not only dependent on biasing positions but also controlled intensity input perturbations. Additionally, explore ability RTD-PDs to perform signal transmission and neuromorphic spike generation simultaneously. These versatile functions indicate...
We present an electroabsorption modulated laser based on identical epitaxial scheme, side-wall grating, on- chip microwave probe interface, and a new low-permittivity planarization method. The modulation speed is significantly increased by reducing the electrode capacitance planarizing with 5-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>-thick HSQ layer. Furthermore, implementing direct ground-signal-ground interface provides straightforward...
In this paper, we present characterization of a compact flat microwave lens operating between 6 GHz and 14 using near field scanning system. An X-band horn antenna open-end rectangular waveguide were used as an illumination source probe, respectively. |S21| is measured the probe moves on plane orthogonal to optical axis vertically horizontally. The made metasurface layer that sandwiched by two layers cross-oriented gratings. overall dimension 10 cm in diameter 0.57 thickness. measurement...
This paper describes the systematic approach to develop low power consumption excitable neuromorphic spike generators using nano-sized resonant tunnelling diode (RTD), including fabrication, characterization and device modelling circuit simulation. The fabrication process of nano sized RTDs has been developed devices exhibit peak currents up 100 μA. energy efficiency RTD generator can reach as 0.09 fJ per spike. An accurate small signal model also is described. nano-RTD technology could...
Abstract Spike-based neuromorphic devices promise to alleviate the energy greed of artificial intelligence hardware by using spiking neural networks (SNNs), which employ neuron like units process information through timing spikes. These neuron-like only consume when active. Recent works have shown that resonant tunnelling diodes (RTDs) incorporating optoelectronic functionalities such as photodetection and light emission can play a major role on photonic SNNs. RTDs are display an N-shaped...
We report a multi-modal spiking neuron that allows optical and electronic input control, wavelength-multiplexing operation, for use in novel high-speed neuromorphic sensing computing functionalities. The photonic-electronic is built with micro-scale, nanostructure resonant tunnelling diode (RTD) photodetection (PD) capability. Leveraging the advantageous intrinsic properties of this RTD-PD system, namely highly nonlinear characteristics, photo-sensitivity, light-induced I-V curve shift,...
Interconnectivity between functional building blocks (such as neurons and synapses) represents a fundamental functionality for realizing neuromorphic systems. However, in the domain of photonics, synaptic interlinking cascadability spiking optical artificial remains challenging mostly unexplored experiments. In this work, we report an link optoelectronic based upon resonant tunneling diodes (RTDs) that allows cascadable spike propagation. First, deterministic is triggered using multimodal...
Abstract We report a multi-modal spiking neuron that allows optical and electronic input control, wavelength-multiplexing operation, for use in novel high-speed neuromorphic sensing computing functionalities. The photonic-electronic is built with micro-scale, nanostructure resonant tunnelling diode (RTD) photodetection (PD) capability. Leveraging the advantageous intrinsic properties of this RTD-PD system, namely highly nonlinear characteristics, photo-sensitivity, light-induced I – V curve...
We report an optoelectronic neuromorphic synaptic link built with high-speed nanoscale resonant tunnelling diode-photodetectors (RTD-PDs), which reproduces temporal-coded spike generation and transmissions in biological neurons synapses. The artificial neuron is composed of a RTD-PD double barrier quantum well (DBQW) structure for nonlinearity excitability, optical-sensitive layer to enable light-triggered firing. Due the effect, RTDs exhibit typical N-shaped current-voltage (I-V) curve...
Excitable optoelectronic devices represent one of the key building blocks for implementation artificial spiking neurons in neuromorphic (brain-inspired) photonic systems. This work introduces and experimentally investigates an opto-electro-optical (O/E/O) neuron built with a resonant tunnelling diode (RTD) coupled to photodetector as receiver vertical cavity surface emitting laser transmitter. We demonstrate well defined excitability threshold, above which this produces 100 ns optical...
Electroabsorption modulated lasers (EMLs), comprising a distributed feedback (DFB) laser and electroabsorption modulator (EAM) monolithically integrated into the same chip, are attractive because of their compact size, low fabrication cost, capability to offer high modulation speed with drive voltage, chirp, extinction ratio [1] , [2] . The EML is limited by RC constant EAM electrode, which conventionally configured either lumped or travelling-wave (TW) electrode. latter approach overcomes...
This work reports a nanostructure resonant tunnelling diode-photodetector (RTD-PD) device and demonstrates its operation as controllable, optically-triggered excitable spike generator. The top contact layer of the is designed with nanopillar structure 500 nm in diameter) to restrain injection current, yielding therefore lower energy for generation. We demonstrate experimentally deterministic optical triggering controllable repeatable neuron-like patterns RTD-PDs. Moreover, we show device's...
We report experimental investigation of time refractory on optoelectronic neuromorphic receiver circuit built with a nanoscale resonant tunnelling diode-photodetector (RTD-PD), capable to produce optically induced spiking events nanosecond repetition rate. RTDs are voltage-controlled nano-electronic semiconductor epilayer elements that includes double barrier quantum well structure which due the effect has an N-shaped current-voltage (IV) curve exhibiting wide-bandwidth negative differential...
In this paper, we present a low-cost, high-gain lens antenna operating at X-band that consists of metasurface-based flat and standard patch antenna. The comprises three layers, including two outer layers cross-polarized gratings meta-atom-based middle layer. feed is in the near field. By designing meta-atoms appropriately, can achieve relative phase shift range from 0° to 360°, which crucial for directing antenna's spherical wavefronts towards lens. area measures 160 mm × mm, with separation...
We report a spiking artificial optoelectronic neuron based on resonant tunnelling diode (RTD) coupled to photodetector (receiver) and vertical cavity surface emitting laser (VCSEL, transmitter). experimentally realize this O/E/O system, demonstrate optical with well-defined, adjustable excitability threshold.
Low-cost solutions for delivering high communication bandwidths in both short- and long-haul systems are urgently required. Electroabsorption modulated lasers (EMLs), comprising a distributed feedback (DFB) laser electroabsorption modulator (EAM), can address this. They compact offer modulation speed with low drive voltage, chirp, extinction ratio [1] . To the best of our knowledge, EAM EMLs based on identical epitaxial layer technology has so far been configured lumped electrode. This take...