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8 pages, 7697 KiB

Open AccessArticle

Polarization-Insensitive Phase Modulators Based on an Embedded Silicon-Graphene-Silicon Waveguide

by Xinhai Zou, Yujia Zhang, Zhihui Li, Yiwei Yang, Shangjian Zhang, Zhiyao Zhang, Yali Zhang and Yong Liu

Appl. Sci. 2019, 9(3), 429; https://doi.org/10.3390/app9030429 - 28 Jan 2019

Cited by 9 | Viewed by 2845

Abstract

A polarization-insensitive phase modulator concept is presented, based on an embedded silicon-graphene-silicon waveguide. Simulation results show that the effective mode index of both transverse electric (TE) and transverse magnetic (TM) modes in the silicon-graphene-silicon waveguide undergoes almost the same variations under different biases [...] Read more.

A polarization-insensitive phase modulator concept is presented, based on an embedded silicon-graphene-silicon waveguide. Simulation results show that the effective mode index of both transverse electric (TE) and transverse magnetic (TM) modes in the silicon-graphene-silicon waveguide undergoes almost the same variations under different biases across a broad wavelength range, in which the real-part difference is less than 1.2 × 10⁻³. Based on that, a polarization-insensitive phase modulator is demonstrated, with a 3-dB modulation bandwidth of 135.6 GHz and a wavelength range of over 500 nm. Moreover, it has a compact size of 60 μm, and a low insertion loss of 2.12 dB. The proposed polarization-insensitive waveguide structure could be also applied to Mach-Zehnder modulators and electro-absorption modulators. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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16 pages, 3031 KiB

Open AccessArticle

A Versatile Silicon-Silicon Nitride Photonics Platform for Enhanced Functionalities and Applications

by Quentin Wilmart, Houssein El Dirani, Nicola Tyler, Daivid Fowler, Stéphane Malhouitre, Stéphanie Garcia, Marco Casale, Sébastien Kerdiles, Karim Hassan, Christelle Monat, Xavier Letartre, Ayman Kamel, Minhao Pu, Kresten Yvind, Leif Katsuo Oxenløwe, Wilfried Rabaud, Corrado Sciancalepore, Bertrand Szelag and Ségolène Olivier

Appl. Sci. 2019, 9(2), 255; https://doi.org/10.3390/app9020255 - 11 Jan 2019

Cited by 78 | Viewed by 7843

Abstract

Silicon photonics is one of the most prominent technology platforms for integrated photonics and can support a wide variety of applications. As we move towards a mature industrial core technology, we present the integration of silicon nitride (SiN) material to extend the capabilities [...] Read more.

Silicon photonics is one of the most prominent technology platforms for integrated photonics and can support a wide variety of applications. As we move towards a mature industrial core technology, we present the integration of silicon nitride (SiN) material to extend the capabilities of our silicon photonics platform. Depending on the application being targeted, we have developed several integration strategies for the incorporation of SiN. We present these processes, as well as key components for dedicated applications. In particular, we present the use of SiN for athermal multiplexing in optical transceivers for datacom applications, the nonlinear generation of frequency combs in SiN micro-resonators for ultra-high data rate transmission, spectroscopy or metrology applications and the use of SiN to realize optical phased arrays in the 800–1000 nm wavelength range for Light Detection And Ranging (LIDAR) applications. These functionalities are demonstrated using a 200 mm complementary metal-oxide-semiconductor (CMOS)-compatible pilot line, showing the versatility and scalability of the Si-SiN platform. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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11 pages, 2134 KiB

Open AccessFeature PaperArticle

Wideband Ge-Rich SiGe Polarization-Insensitive Waveguides for Mid-Infrared Free-Space Communications

by Vladyslav Vakarin, Joan Manel Ramírez, Jacopo Frigerio, Qiankun Liu, Andrea Ballabio, Xavier Le Roux, Carlos Alonso-Ramos, Giovanni Isella, Pavel Cheben, Winnie N. Ye, Laurent Vivien and Delphine Marris-Morini

Appl. Sci. 2018, 8(7), 1154; https://doi.org/10.3390/app8071154 - 16 Jul 2018

Cited by 10 | Viewed by 3739

Abstract

The recent development of quantum cascade lasers, with room-temperature emission in the mid-infrared range, opened new opportunities for the implementation of ultra-wideband communication systems. Specifically, the mid-infrared atmospheric transparency windows, comprising wavelengths between 3–5 µm and 8–14 µm, have great potential for free-space [...] Read more.

The recent development of quantum cascade lasers, with room-temperature emission in the mid-infrared range, opened new opportunities for the implementation of ultra-wideband communication systems. Specifically, the mid-infrared atmospheric transparency windows, comprising wavelengths between 3–5 µm and 8–14 µm, have great potential for free-space communications, as they provide a wide unregulated spectrum with low Mie and Rayleigh scattering and reduced background noise. Despite the great efforts devoted to the development of mid-infrared sources and detectors, little attention is dedicated to the management of polarization for signal processing. In this work, we used Ge-rich SiGe alloys to build a wideband and polarization-insensitive mid-infrared photonic platform. We showed that the gradual index change in the SiGe alloys enabled the design of waveguides with remarkably low birefringence, below 2 × 10⁻⁴, over ultra-wide wavelength ranges within both atmospheric transparency windows, near wavelengths of 3.5 µm and 9 µm. We also report on the design of a polarization-independent multimode interference device achieving efficient power splitting in an unprecedented 4.5-µm bandwidth at around 10-µm wavelength. The ultra-wideband polarization-insensitive building blocks presented here pave the way for the development of high-performance on-chip photonic circuits for next-generation mid-infrared free-space communication systems. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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13 pages, 5783 KiB

Open AccessFeature PaperArticle

Ultra-Low-Loss Silicon Waveguides for Heterogeneously Integrated Silicon/III-V Photonics

by Minh A. Tran, Duanni Huang, Tin Komljenovic, Jonathan Peters, Aditya Malik and John E. Bowers

Appl. Sci. 2018, 8(7), 1139; https://doi.org/10.3390/app8071139 - 13 Jul 2018

Cited by 90 | Viewed by 10366

Abstract

Integrated ultra-low-loss waveguides are highly desired for integrated photonics to enable applications that require long delay lines, high-Q resonators, narrow filters, etc. Here, we present an ultra-low-loss silicon waveguide on 500 nm thick Silicon-On-Insulator (SOI) platform. Meter-scale delay lines, million-Q resonators [...] Read more.

Integrated ultra-low-loss waveguides are highly desired for integrated photonics to enable applications that require long delay lines, high-Q resonators, narrow filters, etc. Here, we present an ultra-low-loss silicon waveguide on 500 nm thick Silicon-On-Insulator (SOI) platform. Meter-scale delay lines, million-Q resonators and tens of picometer bandwidth grating filters are experimentally demonstrated. We design a low-loss low-reflection taper to seamlessly integrate the ultra-low-loss waveguide with standard heterogeneous Si/III-V integrated photonics platform to allow realization of high-performance photonic devices such as ultra-low-noise lasers and optical gyroscopes. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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Review

Jump to: Research

25 pages, 2445 KiB

Open AccessReview

Si Photonics for Practical LiDAR Solutions

by Xiaochen Sun, Lingxuan Zhang, Qihao Zhang and Wenfu Zhang

Appl. Sci. 2019, 9(20), 4225; https://doi.org/10.3390/app9204225 - 10 Oct 2019

Cited by 73 | Viewed by 10054

Abstract

In the article the authors discuss light detection and ranging (LiDAR) for automotive applications and the potential roles Si photonics can play in practice. The authors review published research work on Si photonics optical phased array (OPA) and other relevant devices in the [...] Read more.

In the article the authors discuss light detection and ranging (LiDAR) for automotive applications and the potential roles Si photonics can play in practice. The authors review published research work on Si photonics optical phased array (OPA) and other relevant devices in the past decade with in-depth technical analysis with respect to practical system design considerations. The commercialization status of certain LiDAR technologies is briefly introduced. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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11 pages, 4188 KiB

Open AccessReview

Silicon Meets Graphene for a New Family of Near-Infrared Schottky Photodetectors

by Maurizio Casalino

Appl. Sci. 2019, 9(18), 3677; https://doi.org/10.3390/app9183677 - 05 Sep 2019

Cited by 6 | Viewed by 3250

Abstract

In recent years, graphene has attracted much interest due to its unique properties of flexibility, strong light-matter interaction, high carrier mobility and broadband absorption. In addition, graphene can be deposited on many substrates including silicon with which is able to form Schottky junctions, [...] Read more.

In recent years, graphene has attracted much interest due to its unique properties of flexibility, strong light-matter interaction, high carrier mobility and broadband absorption. In addition, graphene can be deposited on many substrates including silicon with which is able to form Schottky junctions, opening the path to the realization of near-infrared photodetectors based on the internal photoemission effect where graphene plays the role of the metal. In this work, we review the very recent progress of the near-infrared photodetectors based on Schottky junctions involving graphene. This new family of device promises to overcome the limitations of the Schottky photodetectors based on metals showing the potentialities to compare favorably with germanium photodetectors currently employed in silicon photonics. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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15 pages, 4930 KiB

Open AccessReview

O-Band and C/L-Band III-V Quantum Dot Lasers Monolithically Grown on Ge and Si Substrate

by Qi Feng, Wenqi Wei, Bin Zhang, Hailing Wang, Jianhuan Wang, Hui Cong, Ting Wang and Jianjun Zhang

Appl. Sci. 2019, 9(3), 385; https://doi.org/10.3390/app9030385 - 23 Jan 2019

Cited by 27 | Viewed by 4723

Abstract

Direct epitaxial growth of III-V heterostructure on CMOS-compatible silicon wafer offers substantial manufacturing cost and scalability advantages. Quantum dot (QD) devices are less sensitive to defect and temperature, which makes epitaxially grown III-V QD lasers on Si one of the most promising technologies [...] Read more.

Direct epitaxial growth of III-V heterostructure on CMOS-compatible silicon wafer offers substantial manufacturing cost and scalability advantages. Quantum dot (QD) devices are less sensitive to defect and temperature, which makes epitaxially grown III-V QD lasers on Si one of the most promising technologies for achieving low-cost, scalable integration with silicon photonics. The major challenges are that heteroepitaxial growth of III-V materials on Si normally encounters high densities of mismatch dislocations, antiphase boundaries and thermal cracks, which limit the device performance and lifetime. This paper reviews some of the recent developments on hybrid InAs/GaAs QD growth on Ge substrates and highly uniform (111)-faceted hollow Si (001) substrates by molecular beam epitaxy (MBE). By implementing step-graded epitaxial growth techniques, the emission wavelength can be tuned into either an O band or C/L band. Furthermore, microcavity QD laser devices are fabricated and characterized. The epitaxially grown III-V/IV hybrid platform paves the way to provide a promising approach for future on-chip silicon photonic integration. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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18 pages, 1069 KiB

Open AccessReview

Astrophotonic Spectrographs

by Pradip Gatkine, Sylvain Veilleux and Mario Dagenais

Appl. Sci. 2019, 9(2), 290; https://doi.org/10.3390/app9020290 - 15 Jan 2019

Cited by 37 | Viewed by 4533

Abstract

Astrophotonics is the application of photonic technologies to channel, manipulate, and disperse light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. Utilizing photonic advantage for astronomical spectroscopy is a promising approach to miniaturizing the [...] Read more.

Astrophotonics is the application of photonic technologies to channel, manipulate, and disperse light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. Utilizing photonic advantage for astronomical spectroscopy is a promising approach to miniaturizing the next generation of spectrometers for large telescopes. It can be primarily attained by leveraging the two-dimensional nature of photonic structures on a chip or a set of fibers, thus reducing the size of spectroscopic instrumentation to a few centimeters and the weight to a few hundred grams. A wide variety of astrophotonic spectrometers is currently being developed, including arrayed waveguide gratings (AWGs), photonic echelle gratings (PEGs), and Fourier-transform spectrometer (FTS). These astrophotonic devices are flexible, cheaper to mass produce, easier to control, and much less susceptible to vibrations and flexure than conventional astronomical spectrographs. The applications of these spectrographs range from astronomy to biomedical analysis. This paper provides a brief review of this new class of astronomical spectrographs. Full article

(This article belongs to the Special Issue Silicon Photonics – Emerging Devices and Applications)

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