Emerging Technologies 2018 Session Listing
The program is subject to change in the weeks leading up to the conference. Check back here for the latest schedule, or follow us on Twitter for real-time notice of updates to the program.
Session C3: Optics and Photonics
Start Time: 13:30, Thursday, May 10
Room: Diamond Head
Chaired by Sudip Shekhar, University of British Columbia (firstname.lastname@example.org)
- 13:30 Lukas Chrostowski, University of British Columbia
Sub-wavelength silicon photonics and applications
- 13:50 Jonathan Bradley, McMaster University
Rare-earth-doped light-emitting thin films and photonic devices on silicon
Since the 1990s, compact and low cost rare earth integrated amplifiers and lasers have received much attention, particularly for high speed telecommunications applications. Nevertheless, despite many advances, the technology has yet to see widespread application. The primary reason is that fiber-based devices, although bulkier, are very well established, offer good performance and can meet the requirements of larger telecom systems. Recently, however, with the rise of silicon photonics and scaling of transceiver technology in data centers, the demand for compact optical amplifier and light emitter solutions is high. In this talk I will discuss our recent progress in silicon-based rare earth amplifiers and lasers. I will focus on the rare-earth host material aluminum oxide (Al2O2), which exhibits high thermal stability, broad emission spectra, and reduced rare-earth clustering and higher refractive index than other common rare earth host materials such as silica, thus enables smaller devices. We have demonstrated compact erbium-doped waveguide amplifiers and a number of on-chip near-infrared lasers, including distributed feedback, distributed Bragg reflector and microcavity devices. I will discuss the potential for integration of such devices in silicon photonic microsystems.
- 14:10 Rusli, Nanyang Technological University
Si/MoOx heterojunction hybrid solar cell
- 14:30 Harry van der Graaf, National Institute for Subatomic Physics
New developments in the detection of single soft photons
In a single soft photon detector two essential processes occur: photoelectric absorption, converting the photon into a free photoelectron, and the multiplication of this electron, resulting in a detectable charge pulse. In the photomultiplier, amplification-by- multiplication occurs at a dynode, where a multiple of secondary electrons is reflected after the impact of an incoming energetic primary electron. We have developed the transmission dynode "tynode", in the form of a thin layer where secondary electrons are emitted at the bottom side after the impact of a primary electron at the top side. Using Atomic Layer Deposition (ALD) MgO at the emission side, a transmission secondary electron yield of 5.5 has been reached. A stack of 5 - 8 tynodes should produce a charge pulse sufficient to drive (digital) electronics after the impact of a single primary electron. Thanks to the short and identical straight line paths of the electrons crossing the gap between a tynode and the next one, the transient time is in the order of 50 ps, while all secondary electrons arrive within one ps on the readout anode below the tynode stack. By pixelising the anode in the form of a CMOS pixel chip, the required multiplication is minimised, and 2D spatial resolution is realised.
A stack of tynodes could be an alternative for Micro Channel Plates (MCPs), which have been improved significantly during the last decade. The time resolution of a tynode-based detector may potentially be better.
At present, photon detector development is focused on SiPMs because they are cheap, fast and efficient. Their dark noise, however, cannot be suppressed. An MCP or a tynode stack is a noise-free amplifier, but these are always combined with a photocathode with a limited quantum efficiency (QE). The efficiency of a SiPM could be unity in theory, but the ultimate photon detector could be an assembly of a tynode stack or MCP (ultra fast, free of noise) and a high QE photocathode. With new MEMS technology, an active photocathode may be feasible with a QE much larger than the state-of-the-art value of 0.4.
- 14:50 Douglas M. Gill, IBM
Making short reach link transmitter Figure of Merits cognizant of transmission format
The traditional Mach-Zehnder modulator (MZM) figure of merit (FOM) is defined as (V^2)/(Freq_3dBe), and works effectively for LiNbO3 long haul modulators. However, this FOM is inappropriate for plasma dispersion based electro-optic modulators, or any modulator with an inherent relationship between bandwidth, required drive voltage, and optical insertion loss/gain. This FOM is even less relevant for such modulators when used in short reach links with no optical amplification. I will present a newly proposed modulator FOM (M-FOM) based on device metrics that are essential for assessing short-reach link performance, such as peak-to-peak drive voltage, modulator rise-fall time, and relative optical modulation amplitude. In addition, I will discuss how the M-FOM can essentially be made "transmission format aware" by appropriately scaling its value with these essential performance metrics. Furthermore, I will present a novel application protocol for our M-FOM that provides direct insight into the impact that modulator performance has on required optical power for unamplified data links. Finally, I will show that our new M-FOM construct allows, for the first time, a direct comparison between ring and Mach-Zehnder modulators.
- 15:10 COFFEE BREAK
(Mt. Curie Foyer, Sutcliffe Foyer)
- 15:30 Tohru Ishihara, Kyoto University
Nanophotonic arithmetic and logic circuits toward optical in-network computation
- 15:50 Pablo Bianucci, Concordia University
A topological nanobeam microcavity
Photonic crystals in a waveguide can give rise to nanobeam microcavities, where the lateral confinement is given by the waveguide mode, and axial confinement is created by introducing a trivial defect in the photonic crystal. These cavities tend to have small mode volumes and reasonably high quality factors, limited mostly by surface roughness introduced during the fabrication.By moving to a dimerized photonic crystal waveguide, we can create a topological defect in the waveguide that will introduce axial confinement. This topology-induced confinement is robust agains disorder and fabrication-induced roughness. We will discuss the tradeoffs involved in the design of these topological microcavities, and their implementation in a silicon-on-insulator platform.
- 16:10 Andy Knights, McMaster University
with Z. Wang
Resonance control of a silicon micro-ring resonator modulator without the requirement for heterogeneous integration
A method to stabilize the resonance wavelength of a depletion-type silicon micro-ring resonator modulator during high- speed operation will be presented. The method utilizes the intrinsic defect-mediated photo-absorption of a silicon waveguide and results in a modulator chip fabrication process that is free of heterogeneous integration. The residual defects present after p-n junction formation are found to produce an adequate photocurrent for use as a feedback signal, while an integrated heater is used to compensate for thermal drift via closed-loop control. This feedback control method is experimentally demonstrated. The resonance locking is validated for a 10 Gb/s intensity modulation in a back-to-back bit-error-rate measurement, while extension to 28Gb/s is described. The use of intrinsic defects present after standard fabrication insures that no excess loss is associated with this stabilization method.
- 16:30 James A. Lott, Technische Universität Berlin
with G. Larisch and D. Bimberg
Surface emitting lasers for a green internet
The energy required to transmit information as encoded optical and electrical data bits within and between electronic and photonic integrated circuits, within and between computer servers, within and between data centers, and ultimately nearly instantly across the earth from any one point to another clearly must be minimized. This energy spans between typically tens of picojoules-per-bit to well over tens of millijoules-per-bit for the intercontinental distances. We seek to meet the exploding demand for information within the terrestrial resources available but more importantly as a common sense measure to reduce costs and to become stewards of a perpetual Green Internet. The concept of a Green Internet implies a collection of highly energy-efficient, independent, and ubiquitous information systems operating with minimal impact on the environment via natural or sustainable energy sources. A key enabling optical component for the Green Internet is the vertical-cavity surface-emitting laser (VCSEL). We review our research work on energy-efficient VCSELs for application as light-sources for optical interconnects and optical fiber data communications. We present VCSEL designs, design principles, and operating methods that enable data communication systems capable of error-free operation at bit rates exceeding 50 gigabits-per- second with energy efficiencies approaching 100 femtojoules-per-bit
- 16:50 Hengky Chandrahalim, Air Force Institute of Technology
Sustainable whispering-gallery ring laser sensors
We present the recent developments of mechanically, thermally, and chemically robust, sustainable whispering-gallery ring lasers for various sensing applications, fabricated by ultrafast laser inscription and standard lithography processes. Our research group have developed highly versatile optofluidic and solid microring laser systems built on fused-silica substrates. They offer a plethora of advantages over existing integrated microring laser systems, including well-defined ring resonator geometries (shape and size), inherent mechanical and chemical robustness, and regeneration capability. We also report our unique fabrication process to integrate photolithographically fabricated ring lasers and optical waveguides inscribed by ultrashort laser pulses on the same photonic chip. The manufacturing procedure of our optofluidic laser is unique and compelling for various applications as it offers maskless and flexible fabrication process, easy assembly, excellent device robustness, no post-fabrication processes, quick prototyping, and low cost. The successful integration of renewable and wavelength-agile microring lasers with laser inscribed photonic waveguides is expected to enable future on-chip optical sensing and signal processing with much higher complexity. We are currently progressing in our research to use the integrated microring cavity systems to perform temperature, pH, and refractive index sensing, broadband acoustic detection, and photoacoustic imaging.
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