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A CMOS-Compatible Carrier-Injection Plasmonic Micro-Ring Modulator with Resonance Tuning by Carrier Concentration. PHOTONICS 2022. [DOI: 10.3390/photonics9050272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A complementary metal-oxide-semiconductor (CMOS)-compatible carrier-injection plasmonic micro-ring modulator (CIPMRM) is designed and analyzed theoretically. The CIPMRM has a compacted footprint of 49.3 μm2 (R = 2 μm), a bit rate of 36.5 Gbps, insertion loss of −9.8 dB, a static extinction ratio of 21.7 dB, and energy consumption of 4.40 pJ/bit as 2.2 V peak-to-peak voltage is applied at 1550 nm. Besides, the method of resonance tuning by carrier concentration is proposed to compensate for the wavelength mismatch between the CIPMRM resonance and the laser, resulting from temperature and line width variation of the CIPMRM. This method has a faster response time and a greater ability to shift the resonant wavelength compared with the method of thermo-optic resonance tuning. The proposed scheme provides a route for realizing the compacted size modulator for optoelectronic integration.
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A CMOS-Compatible Carrier-Injection Plasmonic Micro-Ring Modulator (CIPMRM) with Stable Performance as Temperature Varying around 60 K. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12083947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A CMOS-compatible carrier-injection plasmonic micro-ring modulator (CIPMRM) is proposed and theoretically analyzed. It has a compacted footprint of 43.4 μm2 (R = 2 μm), a data rate of 45 Gbps, an insertion loss of −8 dB, a static extinction ratio of 22 dB, and an energy consumption of 4.5 pJ/bit when 2.5 V peak-to-peak voltage is applied. Moreover, it works well when temperature varies around 60 K. A method of tuning the resonant wavelength based on the carrier concentration is proposed here because the device is reliable when the linewidth varies within ±5%. CIPMRM provides a way to overcome the shortcomings of temperature and process sensitivity, which are characteristics of the photonic micro-ring modulator. It can be used in optoelectronic integration for its small size and stable performance.
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Weigel PO, Zhao J, Fang K, Al-Rubaye H, Trotter D, Hood D, Mudrick J, Dallo C, Pomerene AT, Starbuck AL, DeRose CT, Lentine AL, Rebeiz G, Mookherjea S. Bonded thin film lithium niobate modulator on a silicon photonics platform exceeding 100 GHz 3-dB electrical modulation bandwidth. OPTICS EXPRESS 2018; 26:23728-23739. [PMID: 30184869 DOI: 10.1364/oe.26.023728] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We demonstrate an ultra-high-bandwidth Mach-Zehnder electro-optic modulator (EOM), based on foundry-fabricated silicon (Si) photonics, made using conventional lithography and wafer-scale fabrication, oxide-bonded at 200C to a lithium niobate (LN) thin film. Our design integrates silicon photonics light input/output and optical components, such as directional couplers and low-radius bends. No etching or patterning of the thin film LN is required. This hybrid Si-LN MZM achieves beyond 106 GHz 3-dB electrical modulation bandwidth, the highest of any silicon photonic or lithium niobate (phase) modulator.
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Abstract
For nearly two decades, the field of plasmonics1 - which studies the coupling of electromagnetic waves to the motion of free electrons in a metal2 - has sought to realize subwavelength optical devices for information technology3–6, sensing7,8, nonlinear optics9,10, optical nanotweezers11 and biomedical applications12. Although the heat generated by ohmic losses is desired for some applications (e.g. photo-thermal therapy), plasmonic devices for sensing and information technology have largely suffered from these losses inherent to metals13. This has led to a widespread stereotype that plasmonics is simply too lossy to be practical. Here, we demonstrate that these losses can be bypassed by employing “resonant switching”. In the proposed approach, light is only coupled to the lossy surface plasmon polaritons in the device’s off-state (in resonance) where attenuation is desired to ensure large extinction ratios and facilitate sub-ps switching. In the on state (out of resonance), light is prevented from coupling to the lossy plasmonic section by destructive interference. To validate the approach, we fabricated a plasmonic electro-optic ring modulator. The experiments confirm that low on-chip optical losses (2.5 dB), high-speed operation (>>100 GHz), good energy efficiency (12 fJ/bit), low thermal drift (4‰ K-1), and a compact footprint (sub-λ radius of 1 μm) can be realized within a single device. Our result illustrates the potential of plasmonics to render fast and compact on-chip sensing and communications technologies.
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Ayata M, Fedoryshyn Y, Heni W, Baeuerle B, Josten A, Zahner M, Koch U, Salamin Y, Hoessbacher C, Haffner C, Elder DL, Dalton LR, Leuthold J. High-speed plasmonic modulator in a single metal layer. Science 2018; 358:630-632. [PMID: 29097545 DOI: 10.1126/science.aan5953] [Citation(s) in RCA: 180] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 09/26/2017] [Indexed: 01/21/2023]
Abstract
Plasmonics provides a possible route to overcome both the speed limitations of electronics and the critical dimensions of photonics. We present an all-plasmonic 116-gigabits per second electro-optical modulator in which all the elements-the vertical grating couplers, splitters, polarization rotators, and active section with phase shifters-are included in a single metal layer. The device can be realized on any smooth substrate surface and operates with low energy consumption. Our results show that plasmonics is indeed a viable path to an ultracompact, highest-speed, and low-cost technology that might find many applications in a wide range of fields of sensing and communications because it is compatible with and can be placed on a wide variety of materials.
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Affiliation(s)
- Masafumi Ayata
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland.
| | - Yuriy Fedoryshyn
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Wolfgang Heni
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Benedikt Baeuerle
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Arne Josten
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Marco Zahner
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Ueli Koch
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Yannick Salamin
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Claudia Hoessbacher
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Christian Haffner
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland
| | - Delwin L Elder
- University of Washington, Department of Chemistry, Seattle, WA 98195-1700, USA
| | - Larry R Dalton
- University of Washington, Department of Chemistry, Seattle, WA 98195-1700, USA
| | - Juerg Leuthold
- ETH Zurich, Institute of Electromagnetic Fields (IEF), 8092 Zurich, Switzerland.
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Jin L, Wen L, Liang L, Chen Q, Sun Y. Polarization-Insensitive Surface Plasmon Polarization Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide. NANOSCALE RESEARCH LETTERS 2018; 13:39. [PMID: 29396620 PMCID: PMC5796959 DOI: 10.1186/s11671-018-2446-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific polarization state. In this case, it will lead to a high polarization dependent loss, when the polarization-sensitive modulator integrates to a fiber with random polarization state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and horizontal polarized guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the polarization state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both polarizations in our proposed modulator. Further, the polarization-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and horizontal polarized modes. For the optimized geometry configuration, the difference between the ER values of two polarization modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both polarizations at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random polarization state.
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Affiliation(s)
- Lin Jin
- Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences(CAS), Suzhou, 215123 People’s Republic of China
| | - Long Wen
- Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences(CAS), Suzhou, 215123 People’s Republic of China
| | - Li Liang
- Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences(CAS), Suzhou, 215123 People’s Republic of China
| | - Qin Chen
- Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences(CAS), Suzhou, 215123 People’s Republic of China
| | - Yunfei Sun
- School of Electronic & Information Engineering, Suzhou University of Sciences and Technology, Suzhou, Jiangsu 215009 People’s Republic of China
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Kamada S, Okamoto T, El-Zohary SE, Haraguchi M. Design optimization and fabrication of Mach- Zehnder interferometer based on MIM plasmonic waveguides. OPTICS EXPRESS 2016; 24:16224-16231. [PMID: 27464075 DOI: 10.1364/oe.24.016224] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We proposed and designed a compact unbalanced Mach-Zehnder interferometer (MZI) based on metal/insulator/metal (MIM) plasmonic waveguides for ultrafast optical signal processing. The MZI was fabricated by a lithography technique and we provide, for the first time experimental evaluation of the transmission performance of the MZI using MIM PWGs. The experimental results were in good agreement with the numerical simulations. The proposed structure could be considered as a key device for on-chip optical integrated circuits.
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Nielsen MP, Lafone L, Rakovich A, Sidiropoulos TPH, Rahmani M, Maier SA, Oulton RF. Adiabatic Nanofocusing in Hybrid Gap Plasmon Waveguides on the Silicon-on-Insulator Platform. NANO LETTERS 2016; 16:1410-4. [PMID: 26771836 DOI: 10.1021/acs.nanolett.5b04931] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We present an experimental demonstration of a new class of hybrid gap plasmon waveguides on the silicon-on-insulator (SOI) platform. Created by the hybridization of the plasmonic mode of a gap in a thin metal sheet and the transverse-electric (TE) photonic mode of an SOI slab, this waveguide is designed for efficient adiabatic nanofocusing simply by varying the gap width. For gap widths greater than 100 nm, the mode is primarily photonic in character and propagation lengths can be many tens of micrometers. For gap widths below 100 nm, the mode becomes plasmonic in character with field confinement predominantly within the gap region and with propagation lengths of a few microns. We estimate the electric field intensity enhancement in hybrid gap plasmon waveguide tapers at 1550 nm by three-photon absorption of selectively deposited CdSe/ZnS quantum dots within the gap. Here, we show electric field intensity enhancements of up to 167 ± 26 for a 24 nm gap, proving the viability of low loss adiabatic nanofocusing on a commercially relevant photonics platform.
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Affiliation(s)
- Michael P Nielsen
- Department of Physics, Imperial College London , London, SW7 2AZ, United Kingdom
| | - Lucas Lafone
- Department of Physics, Imperial College London , London, SW7 2AZ, United Kingdom
| | - Aliaksandra Rakovich
- Department of Physics, Imperial College London , London, SW7 2AZ, United Kingdom
| | | | - Mohsen Rahmani
- Department of Physics, Imperial College London , London, SW7 2AZ, United Kingdom
| | - Stefan A Maier
- Department of Physics, Imperial College London , London, SW7 2AZ, United Kingdom
| | - Rupert F Oulton
- Department of Physics, Imperial College London , London, SW7 2AZ, United Kingdom
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Olivieri A, Chen C, Hassan S, Lisicka-Skrzek E, Tait RN, Berini P. Plasmonic nanostructured metal-oxide-semiconductor reflection modulators. NANO LETTERS 2015; 15:2304-2311. [PMID: 25730698 DOI: 10.1021/nl504389f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We propose a plasmonic surface that produces an electrically controlled reflectance as a high-speed intensity modulator. The device is conceived as a metal-oxide-semiconductor capacitor on silicon with its metal structured as a thin patch bearing a contiguous nanoscale grating. The metal structure serves multiple functions as a driving electrode and as a grating coupler for perpendicularly incident p-polarized light to surface plasmons supported by the patch. Modulation is produced by charging and discharging the capacitor and exploiting the carrier refraction effect in silicon along with the high sensitivity of strongly confined surface plasmons to index perturbations. The area of the modulator is set by the area of the incident beam, leading to a very compact device for a strongly focused beam (∼2.5 μm in diameter). Theoretically, the modulator can operate over a broad electrical bandwidth (tens of gigahertz) with a modulation depth of 3 to 6%, a loss of 3 to 4 dB, and an optical bandwidth of about 50 nm. About 1000 modulators can be integrated over a 50 mm(2) area producing an aggregate electro-optic modulation rate in excess of 1 Tb/s. We demonstrate experimentally modulators operating at telecommunications wavelengths, fabricated as nanostructured Au/HfO2/p-Si capacitors. The modulators break conceptually from waveguide-based devices and belong to the same class of devices as surface photodetectors and vertical cavity surface-emitting lasers.
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Affiliation(s)
- Anthony Olivieri
- †School of Electrical Engineering and Computer Science, University of Ottawa, 800 King Edward Avenue, Ottawa, Ontairo K1N 6N5, Canada
| | - Chengkun Chen
- †School of Electrical Engineering and Computer Science, University of Ottawa, 800 King Edward Avenue, Ottawa, Ontairo K1N 6N5, Canada
| | - Sa'ad Hassan
- ‡Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Streey, Ottawa, Ontairo K1N 6N5, Canada
| | - Ewa Lisicka-Skrzek
- †School of Electrical Engineering and Computer Science, University of Ottawa, 800 King Edward Avenue, Ottawa, Ontairo K1N 6N5, Canada
| | - R Niall Tait
- §Department of Electronics, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Pierre Berini
- †School of Electrical Engineering and Computer Science, University of Ottawa, 800 King Edward Avenue, Ottawa, Ontairo K1N 6N5, Canada
- ∥Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada
- ⊥Centre for Research in Photonics at the University of Ottawa, 800 King Edward Avenue, Ottawa, Ontario K1N 6N5, Canada
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10
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Song EY, Cho J, Kim H, Choi WY, Lee B. Double bi-material cantilever structures for complex surface plasmon modulation. OPTICS EXPRESS 2015; 23:5500-5507. [PMID: 25836783 DOI: 10.1364/oe.23.005500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A complex modulation structure of surface plasmon polaritons using double bi-material cantilevers is proposed. It is shown with numerical analysis that the thermally controlled mechanical actuation of double bi-material cantilevers can modulate the amplitude and phase of surface plasmon polaritons across a full complex modulation range independently and simultaneously. The complex modulation structures designed for visible wavelengths are presented and their multi-wavelength integration is discussed.
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11
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Hassan S, Lisicka-Skrzek E, Olivieri A, Tait RN, Berini P. Fabrication of a plasmonic modulator incorporating an overlaid grating coupler. NANOTECHNOLOGY 2014; 25:495202. [PMID: 25414162 DOI: 10.1088/0957-4484/25/49/495202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The fabrication of a novel plasmonic reflection modulator is presented and described. The modulator includes plasmon excitation using a diffraction grating coupler and is based on a metal-insulator-semiconductor structure on silicon. Fabrication includes a thin thermal oxide, a plasmonic metal surface defined by optical lithography, a metal grating coupler defined by overlaid e-beam lithography, a passivation layer with metalized vias, and electrical contacts. Physical characterization of intermediate structures is provided along with modulation measurements at λ0 ∼ 1550 nm which verify the concept.
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Affiliation(s)
- Sa'ad Hassan
- Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur St., Ottawa, ON K1N 6N5, Canada
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12
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Lee HW, Papadakis G, Burgos SP, Chander K, Kriesch A, Pala R, Peschel U, Atwater HA. Nanoscale conducting oxide PlasMOStor. NANO LETTERS 2014; 14:6463-6468. [PMID: 25302668 DOI: 10.1021/nl502998z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We experimentally demonstrate an ultracompact PlasMOStor, a plasmon slot waveguide field-effect modulator based on a transparent conducting oxide active region. By electrically modulating the conducting oxide material deposited into the gaps of highly confined plasmonic slot waveguides, we demonstrate field-effect dynamics giving rise to modulation with high dynamic range (2.71 dB/μm) and low waveguide loss (∼0.45 dB/μm). The large modulation strength is due to the large change in complex dielectric function when the signal wavelength approaches the surface plasmon resonance in the voltage-tuned conducting oxide accumulation layer. The results provide insight about the design of ultracompact, nanoscale modulators for future integrated nanophotonic circuits.
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Affiliation(s)
- Ho W Lee
- Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology , Pasadena, California 91125, United States
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Zhu S, Lo GQ, Kwong DL. Design of an ultra-compact electro-absorption modulator comprised of a deposited TiN/HfO₂/ITO/Cu stack for CMOS backend integration. OPTICS EXPRESS 2014; 22:17930-17947. [PMID: 25089413 DOI: 10.1364/oe.22.017930] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An ultra-compact electro-absorption (EA) modulator operating around 1.55-μm telecom wavelengths is proposed and theoretically investigated. The modulator is comprised of a stack of TiN/HfO2</ITO/Cu conformally deposited on a single-mode stripe waveguide to form a hybrid plasmonic waveguide (HPW). Since the thin ITO layer can behave as a semiconductor, the stack itself forms a MOS capacitor. A voltage is applied between the Cu and TiN layers to change the electron concentration of ITO (NITO), which in turn changes its permittivity as well as the propagation loss of HPW. For a HPW comprised of a Cu/3-nm-ITO/5-nm-HfO2/5-nm-TiN stack on a 400-nm × 340-nm-Si stripe waveguide, the propagation loss for the 1.55-μm TE (TM) mode increases from 1.6 (1.4) to 23.2 (23.9) dB/μm when the average NITO in the 3-nm ITO layer increases from 2 × 10(20) to 7 × 10(20) cm(-3), which is achieved by varying the voltage from -2 to 4 V if the initial NITO is 3.5 × 10(20) cm(-3). As a result, a 1-μm-long EA modulator inserted in the 400-nm × 340-nm-Si stripe waveguide exhibits insertion loss of 2.9 (3.2) dB and modulation depth of 19.9 (15.2) dB for the TE (TM) mode. The modulation speed is ~11 GHz, limited by the RC delay, and the energy consumption is ~0.4 pJ/bit. The stack can also be deposited on a low-index-contrast waveguide such as Si3N4. For example, a 4-μm-long EA modulator inserted in an 800-nm × 600-nm-Si3N4 stripe waveguide exhibits insertion loss of 6.3 (3.5) dB and modulation depth of 16.5 (15.8) dB for the TE (TM) mode. The influences of the ITO, TiN, HfO2 layers and the beneath dielectric core, as well as the processing tolerance, on the performance of the proposed EA modulator are systematically investigated.
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Zhu S, Lo GQ, Kwong DL. Silicon nitride based plasmonic components for CMOS back-end-of-line integration. OPTICS EXPRESS 2013; 21:23376-23390. [PMID: 24104251 DOI: 10.1364/oe.21.023376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Silicon nitride waveguides provide low propagation loss but weak mode confinement due to the relatively small refractive index contrast between the Si₃N₄ core and the SiO2 cladding. On the other hand, metal-insulator-metal (MIM) plasmonic waveguides offer strong mode confinement but large propagation loss. In this work, MIM-like plasmonic waveguides and passive devices based on horizontal Cu-Si₃N₄-Cu or Cu-SiO₂-Si₃N₄-SiO₂-Cu structures are integrated in the conventional Si₃N₄ waveguide circuits using standard CMOS backend processes, and are characterized around 1550-nm telecom wavelengths using the conventional fiber-waveguide-fiber method. The Cu-Si₃N₄(~100 nm)-Cu devices exhibit ~0.78-dB/μm propagation loss for straight waveguides, ~38% coupling efficiency with the conventional 1-μm-wide Si₃N₄ waveguide through a 2-μm-long taper coupler, ~0.2-dB bending loss for sharp 90° bends, and ~0.1-dB excess loss for ultracompact 1 × 2 and 1 × 4 power splitters. Inserting a ~10-nm SiO₂ layer between the Si3N4 core and the Cu cover (i.e., the Cu-SiO2(~10 nm)-Si₃N₄(~100 nm)-SiO2(~10 nm)-Cu devices), the propagation loss and the coupling efficiency are improved to ~0.37 dB/μm and ~52% while the bending loss and the excess loss are degraded to ~3.2 dB and ~2.1 dB, respectively. These experimental results are roughly consistent with the numerical simulation results after taking the influence of possible imperfect fabrication into account. Ultracompact plasmonic ring resonators with 1-μm radius are demonstrated with an extinction ratio of ~18 dB and a quality factor of ~84, close to the theoretical prediction.
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Nielsen MP, Elezzabi AY. Ultrafast all-optical modulation in a silicon nanoplasmonic resonator. OPTICS EXPRESS 2013; 21:20274-20279. [PMID: 24105573 DOI: 10.1364/oe.21.020274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Ultrafast all-optical modulation in silicon-based metal-insulator-semiconductor-insulator-metal nanoring resonators through photogeneration of free-carriers using two-photon absorption is presented 3-D through finite difference time domain simulations. In a compact device footprint of only 1.4 µm(2), a 13.1 dB modulation amplitude was obtained with a switching time of only 2 ps using a modest pump pulse energy of 16.0 pJ. The larger bandwidth associated with more compact nanorings is shown to result in increased modulation amplitude.
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16
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Zhu S, Lo GQ, Kwong DL. Theoretical investigation of ultracompact and athermal Si electro-optic modulator based on Cu-TiO2-Si hybrid plasmonic donut resonator. OPTICS EXPRESS 2013; 21:12699-12712. [PMID: 23736489 DOI: 10.1364/oe.21.012699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An ultracompact silicon electro-optic modulator operating at 1550-nm telecom wavelengths is proposed and analyzed theoretically, which consists of a Cu-TiO(2)-Si hybrid plasmonic donut resonator evanescently coupled with a conventional Si channel waveguide. Owing to a negative thermo-optic coefficient of TiO(2) (~-1.8 × 10(-4) K(-1)), the real part of effective modal index of the curved Cu-TiO(2)-Si hybrid waveguide can be temperature-independent (i.e., athermal) if the TiO(2) interlayer and the beneath Si core have a certain thickness ratio. A voltage applied between the ring-shaped Cu cap and a cylinder metal electrode positioned at the center of the donut,--which makes Ohmic contact to Si, induces a ~1-nm-thick free-electron accumulation layer at the TiO(2)/Si interface. The optical field intensity in this thin accumulation layer is significantly enhanced if the accumulation concentration is sufficiently large (i.e., > ~6 × 10(20) cm(-3)), which in turn modulates both the resonance wavelengths and the extinction ratio of the donut resonator simultaneously. For a modulator with the total footprint inclusive electrodes of ~8.6 μm(2), 50-nm-thick TiO(2), and 160-nm-thick Si core, FDTD simulation predicts that it has an insertion loss of ~2 dB, a modulation depth of ~8 dB at a voltage swing of ~6 V, a speed-of-response of ~35 GHz, and a switching energy of ~0.45 pJ/bit, and it is athermal around room temperature. The modulator's performances can be further improved by optimization of the coupling strength between the bus waveguide and the donut resonator.
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Affiliation(s)
- Shiyang Zhu
- Institute of Microelectronics, Agency for Science, Technology and Research, 11 Science Park Road, Science Park-II, 117685 Singapore.
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