Aaron Zilkie

Bio: Aaron Zilkie is an academic researcher. The author has contributed to research in topics: Silicon photonics & Photonics. The author has an hindex of 1, co-authored 1 publications receiving 682 citations.

Roadmap on silicon photonics

Abstract: Silicon photonics research can be dated back to the 1980s. However, the previous decade has witnessed an explosive growth in the field. Silicon photonics is a disruptive technology that is poised to revolutionize a number of application areas, for example, data centers, high-performance computing and sensing. The key driving force behind silicon photonics is the ability to use CMOS-like fabrication resulting in high-volume production at low cost. This is a key enabling factor for bringing photonics to a range of technology areas where the costs of implementation using traditional photonic elements such as those used for the telecommunications industry would be prohibitive. Silicon does however have a number of shortcomings as a photonic material. In its basic form it is not an ideal material in which to produce light sources, optical modulators or photodetectors for example. A wealth of research effort from both academia and industry in recent years has fueled the demonstration of multiple solutions to these and other problems, and as time progresses new approaches are increasingly being conceived. It is clear that silicon photonics has a bright future. However, with a growing number of approaches available, what will the silicon photonic integrated circuit of the future look like? This roadmap on silicon photonics delves into the different technology and application areas of the field giving an insight into the state-of-the-art as well as current and future challenges faced by researchers worldwide. Contributions authored by experts from both industry and academia provide an overview and outlook for the silicon waveguide platform, optical sources, optical modulators, photodetectors, integration approaches, packaging, applications of silicon photonics and approaches required to satisfy applications at mid-infrared wavelengths. Advances in science and technology required to meet challenges faced by the field in each of these areas are also addressed together with predictions of where the field is destined to reach.

Demonstration of Fan-out Silicon Photonics Module for Next Generation Co-Packaged Optics (CPO) Application

Abstract: This paper presents the design and demonstration of a co-packaged optical engine using Rockley’s co-designed chipsets, where the fan-out Electrical IC (EIC) substrate is flip-chip bonded to the Photonics Integrated Circuit (PIC), then socketed to the switch ASIC board. Combining fan-out, flip-chip, and socketing optimizes signal integrity and material/packaging cost for the PIC and EIC, while maximizing integration density and rework-ability of the optical engines. The proof-of-concept is realized using our 25 Gbps/ch chipset, and the testing results proved that, not only does our packaging method enable fully functional testing, its impact to the bandwidth of the chipset is negligible. Therefore, the optical engine packaging can be applied to next generation chipset without losing signal integrity and power.

Harnessing plasma absorption in silicon MOS ring modulators

Abstract: High-bandwidth, low-power and compact silicon electro-optical modulators are essential for future energy-efficient and densely integrated optical data communication circuits. The all-silicon plasma-dispersion-effect ring resonator modulator is an attractive prospect. However, its performance is currently limited by the trade-off between modulation depth and switching speed, dictated by its quality factor. Here we introduce a mechanism to leap beyond this limitation by harnessing the plasma absorption induced in a silicon metal–oxide–semiconductor waveguide to enhance the extinction ratio of a low-quality-factor, high-speed ring modulator. The fabricated devices demonstrate a modulation depth of ~27 dB for a bias of ~3.5 V. Modulation enhancement has been observed for operation frequencies ranging from kilohertz to gigahertz, with data modulation up to 100 Gbit s−1 on–off keying demonstrated, paving a way to the evolution of optical interconnects to 100 Gbaud and beyond per wavelength. The plasma absorption effect is demonstrated to enhance the performance of silicon ring modulators.

Pioneering Silicon Photonics for Wearable Sensors

Abstract: The Rockley silicon photonics platform has unique advantages perfectly suited to addressing the needs of wearable health sensors. An overview of the platform is presented including its application to non-invasive continuous monitoring of body temperature.

High-Speed SiGe EAMs at Cryogenic Temperatures

Abstract: Electro-optic modulators capable of operating at cryogenic temperatures are of interest to a host of sensing, quantum, and supercomputing applications. Silicon photonics is compelling for its low cost and CMOS compatibility, but conventional tuning mechanisms are impacted at low temperatures. Bulk electro-absorption modulators are appealing since only the wavelength of the absorption band edge varies with temperature. Cryogenic effects on a fabricated high-speed modulator are shown, with consistent extinction ratio from 5-300K. (Abstract)

Trapped-ion quantum computing: Progress and challenges

Abstract: Trapped ions are among the most promising systems for practical quantum computing (QC). The basic requirements for universal QC have all been demonstrated with ions, and quantum algorithms using few-ion-qubit systems have been implemented. We review the state of the field, covering the basics of how trapped ions are used for QC and their strengths and limitations as qubits. In addition, we discuss what is being done, and what may be required, to increase the scale of trapped ion quantum computers while mitigating decoherence and control errors. Finally, we explore the outlook for trapped-ion QC. In particular, we discuss near-term applications, considerations impacting the design of future systems of trapped ions, and experiments and demonstrations that may further inform these considerations.

Material platforms for spin-based photonic quantum technologies

Abstract: A central goal in quantum optics and quantum information science is the development of quantum networks to generate entanglement between distributed quantum memories. Experimental progress relies on the quality and efficiency of the light–matter quantum interface connecting the quantum states of photons to internal states of quantum emitters. Quantum emitters in solids, which have properties resembling those of atoms and ions, offer an opportunity for realizing light–matter quantum interfaces in scalable and compact hardware. These quantum emitters require a material platform that enables stable spin and optical properties, as well as a robust manufacturing of quantum photonic circuits. Because no emitter system is yet perfect and different applications may require different properties, several light–matter quantum interfaces are being developed in various platforms. This Review highlights the progress in three leading material platforms: diamond, silicon carbide and atomically thin semiconductors. Atom-like quantum emitters in solids have emerged as promising building blocks for quantum information processing. In this Review, recent advances in three leading material platforms—diamond, silicon carbide and atomically thin semiconductors—are summarized, with a focus on applications in quantum networks

Integrated microwave photonics

Abstract: Recent advances in photonic integration have propelled microwave photonic technologies to new heights. The ability to interface hybrid material platforms to enhance light–matter interactions has led to the development of ultra-small and high-bandwidth electro-optic modulators, low-noise frequency synthesizers and chip signal processors with orders-of-magnitude enhanced spectral resolution. On the other hand, the maturity of high-volume semiconductor processing has finally enabled the complete integration of light sources, modulators and detectors in a single microwave photonic processor chip and has ushered the creation of a complex signal processor with multifunctionality and reconfigurability similar to electronic devices. Here, we review these recent advances and discuss the impact of these new frontiers for short- and long-term applications in communications and information processing. We also take a look at the future perspectives at the intersection of integrated microwave photonics and other fields including quantum and neuromorphic photonics. This Review discusses recent advances of microwave photonic technologies and their applications in communications and information processing, as well as their potential implementations in quantum and neuromorphic photonics.

Neuromorphic photonic networks using silicon photonic weight banks.

Abstract: Photonic systems for high-performance information processing have attracted renewed interest. Neuromorphic silicon photonics has the potential to integrate processing functions that vastly exceed the capabilities of electronics. We report first observations of a recurrent silicon photonic neural network, in which connections are configured by microring weight banks. A mathematical isomorphism between the silicon photonic circuit and a continuous neural network model is demonstrated through dynamical bifurcation analysis. Exploiting this isomorphism, a simulated 24-node silicon photonic neural network is programmed using “neural compiler” to solve a differential system emulation task. A 294-fold acceleration against a conventional benchmark is predicted. We also propose and derive power consumption analysis for modulator-class neurons that, as opposed to laser-class neurons, are compatible with silicon photonic platforms. At increased scale, Neuromorphic silicon photonics could access new regimes of ultrafast information processing for radio, control, and scientific computing.

Attojoule Optoelectronics for Low-Energy Information Processing and Communications

Abstract: Optics offers unique opportunities for reducing energy in information processing and communications while simultaneously resolving the problem of interconnect bandwidth density inside machines. Such energy dissipation overall is now at environmentally significant levels; the source of that dissipation is progressively shifting from logic operations to interconnect energies. Without the prospect of substantial reduction in energy per bit communicated, we cannot continue the exponential growth of our use of information. The physics of optics and optoelectronics fundamentally addresses both interconnect energy and bandwidth density, and optics may be the only scalable solution to such problems. Here we summarize the corresponding background, status, opportunities, and research directions for optoelectronic technology and novel optics, including subfemtojoule devices in waveguide and novel two-dimensional (2-D) array optical systems. We compare different approaches to low-energy optoelectronic output devices and their scaling, including lasers, modulators and LEDs, optical confinement approaches (such as resonators) to enhance effects, and the benefits of different material choices, including 2-D materials and other quantum-confined structures. With such optoelectronic energy reductions, and the elimination of line charging dissipation by the use optical connections, the next major interconnect dissipations are in the electronic circuits for receiver amplifiers, timing recovery, and multiplexing. We show we can address these through the integration of photodetectors to reduce or eliminate receiver circuit energies, free-space optics to eliminate the need for timing and multiplexing circuits (while also solving bandwidth density problems), and using optics generally to save power by running large synchronous systems. One target concept is interconnects from ∼1 cm to ∼10 m that have the same energy (∼10 fJ/bit) and simplicity as local electrical wires on chip.