Silicon Photonics technology is rapidly maturing as a platform for larger-scale photonic circuits. As a result, the associated design methodologies are also evolving from componentoriented design to a more circuit-oriented design flow, that makes abstraction from the very detailed geometry and enables design on a larger scale. In this paper, we review the state of this emerging photonic circuit design flow and its synergies with electronic design automation (EDA). We cover the design flow from schematic capture, circuit simulation, layout and verification. We discuss the similarities and the differences between photonic and electronic design, and the challenges and opportunities that present themselves in the new photonic design landscape, such as variability analysis, photonic-electronic co-simulation and compact model definition. Silicon Photonics Circuit Design: Methods, Tools and

https://www.onlinelibrary.wiley.com/doi/epdf/10.1002/lpor.201700237

Silicon Photonics Circuit Design: Methods, Tools and Challenges

Advances in photonic integrated circuits have recently enabled electrically reconfigurable optical systems that can implement universal linear optics transformations on spatial mode sets. This review paper covers progress in such “programmable nanophotonic processors” as well as emerging applications of the technology to problems including classical and quantum information processing and machine learning.

Linear programmable nanophotonic processors

The modulator is a key component in optical communications. Several graphene-based amplitude modulators have been reported based on electro-absorption. However, graphene phase modulators (GPMs) are necessary for functions such as applying complex modulation formats or making switches or phased arrays. Here, we present a 10 Gb s–1 GPM integrated in a Mach–Zehnder interferometer configuration. This is a compact device based on a graphene-insulator–silicon capacitor, with a phase-shifter length of 300 μm and extinction ratio of 35 dB. The GPM has a modulation efficiency of 0.28 V cm at 1,550 nm. It has 5 GHz electro-optical bandwidth and operates at 10 Gb s–1 with 2 V peak-to-peak driving voltage in a push–pull configuration for binary transmission of a non-return-to-zero data stream over 50 km of single-mode fibre. This device is the key building block for graphene-based integrated photonics, enabling compact and energy-efficient hybrid graphene–silicon modulators for telecom, datacom and other applications. A 10 Gb s–1 phase modulator based on a graphene-on-silicon Mach–Zehnder interferometer (MZI) is reported. The compact device has a phase-shifter length of only 300 μm and provides modulation of light at 1,550 nm with a 35 dB extinction ratio.

Graphene-silicon phase modulators with gigahertz bandwidth

Integrated photonics offers great potential for quantum communication devices in terms of complexity, robustness, and scalability. Silicon photonics in particular is a leading platform for quantum photonic technologies, with further benefits of miniaturization, cost-effective device manufacture, and compatibility with CMOS microelectronics. However, effective techniques for high-speed modulation of quantum states in standard silicon photonic platforms have been limited. Here we overcome this limitation and demonstrate high-speed low-error quantum key distribution modulation with silicon photonic devices combining slow thermo-optic DC biases and fast (10 GHz bandwidth) carrier-depletion modulation. The ability to scale up these integrated circuits and incorporate microelectronics opens the way to new and advanced integrated quantum communication technologies and larger adoption of quantum-secured communications.

/pdf/integrated-silicon-photonics-for-high-speed-quantum-key-1iv2u7ky89.pdf

Integrated silicon photonics for high-speed quantum key distribution

We demonstrate a 10Gb/s Graphene Phase Modulator (GPM) integrated in a Mach-Zehnder interferometer configuration. This is a compact device, with a phase-shifter length of only 300$\mu$m, and 35dB extinction ratio. The GPM has modulation efficiency of 0.28Vcm, one order of magnitude higher compared to state-of-the-art depletion p-n junction Si phase modulators. Our GPM operates with 2V peak-to-peak driving voltage in a push-pull configuration, and it has been tested in a binary transmission of a non-return-to-zero data stream over 50km single mode fibre. This device is the key building block for graphene-based integrated photonics, enabling compact and energy efficient hybrid Si-graphene modulators for telecom, datacom and other applications

Graphene Phase Modulator

Silicon photonics has become in the past years an important technology adopted by a growing number of
industrial players to develop their next generation optical transceivers. However most of the technology
platforms established in CMOS fabrication lines are kept captive or open to only a restricted number of
customers. In order to make silicon photonics accessible to a large number of players several initiatives exist
around the world to develop open platforms. In this paper we will present imec’s silicon photonics active
platform accessible through multi-project wafer runs.

Imec iSiPP25G silicon photonics: a robust CMOS-based photonics technology platform

We report on electro-optical device performance in a fully integrated 25Gb/s Si photonics platform running on a 130-nm CMOS toolset. Extensive uniformity data is presented for ring modulators, Ge photodetectors and compact ring-based WDM filters.

Highly Uniform 25 Gb/s Si Photonics Platform for High-Density, Low-Power WDM Optical Interconnects

Silicon photonics technologies are a particularly attractive solution for developing low-cost optical interconnects with high performance. Imec is developing a silicon photonics technology platform. Developing this platform requires continuous process optimization and design verification, both of which are enabled by the flexible wafer-level test solution that is presented in this paper. The test station enables semi-automatic optical and electro-optical testing of passive and active silicon photonics components and circuits, including waveguides, fiber grating couplers, photodetectors, modulators, filters etc. The measured insertion loss of fiber grating couplers is repeatable to within 0.07dB (6σ), for photodetector responsivity the repeatability is around 0.02A/W (6σ). Calibration procedures have been designed to ensure the long-term reproducibility of measurement results. This is demonstrated with wafer-level measurement data for fiber grating couplers and photodetectors that were gathered over a five-month period. The reproducibility over this period is 0.8dB for the insertion loss and 0.09A/W for the responsivity measurement.

Test-station for flexible semi-automatic wafer-level silicon photonics testing

Photodétecteur germanium à avalanche intégré

High speed directly modulated single mode lasers are becoming important optical components for the short reach communication. On the other hand, Si photonics opens up new opportunities to explore the transceivers for the short reach applications. We have fabricated a heterogeneously integrated DFB laser on a Si photonic circuit as a transmitter. For the receiver, a low voltage Si waveguide-coupled Ge avalanche photodetector has been used. We have successfully demonstrated error free transmission of a 10 Gb/s NRZ-OOK signal over 20 km single mode fiber using a silicon on insulator (SOI) based transmitter and receiver.

https://biblio.ugent.be/publication/8539773/file/8539777.pdf

Hongtao Chen

Papers

Imec iSiPP25G silicon photonics: a robust CMOS-based photonics technology platform

Highly Uniform 25 Gb/s Si Photonics Platform for High-Density, Low-Power WDM Optical Interconnects

Test-station for flexible semi-automatic wafer-level silicon photonics testing

Photodétecteur germanium à avalanche intégré

Towards Si photonics based transceivers using directly modulated heterogeneously integrated DFB lasers