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Reconfigurable Photonic Circuits

Research Area: Large-scale Photonic Integration

Main Researcher: Wim Bogaerts

Programmable PICs consists of a mesh of optical waveguides which are coupled together using tunable couplers that can be electrically controlled. Our initial demonstration, the first programmable PIC in silicon photonics, was a simple 4x4 beam coupler that could map 4 inputs onto 4 outputs in any arbitrary linear combination. Such ‘forward-only’ circuits are especially useful in applications that require accelerated matrix operations, such as neural networks and quantum computing. But they are limited when it comes to more advanced functions such as the construction of optical wavelength filters.

Therefore we switched to ‘recirculating’ meshes, where the light can be routed in loops. We study different connectivity schemes for such meshes, and how accurately they need to be controlled to avoid unwanted effects due to unwanted waveguide paths. Because all elements on the photonic chip need to be electrically controlled, we are building an electrical layer based on commercial FPGAs that allows us to digitally control a large number of the on-chip heaters which are used to tune the couplers. Our custom-designed heaters in IMEC’s silicon Photonics Platform allow us to use matrix addressing, drastically reducing the number of electrical connections needed to drive hundreds of tuners on our chip.

Different technology aspects of a programmable photonic chip
Different technology aspects of a programmable photonic chip

Our chip consists of a hexagonal waveguide mesh of 49 ‘cores’, and is capable of handling up to 16 optical fibers as either inputs or outputs, but it also sports 4 high-speed microwave inputs and 8 microwave outputs. This chip now serves as a platform to develop the higher levels of control circuits and configuration algorithms which we have developed, such as routing multiple light paths simultaneously, or distribution trees.

Out 49-core programmable PIC
Out 49-core programmable PIC

We want to program our circuit for multiple applications, like a spectrometer or switch. With its built-in modulators and detectors it can function as an optical transmitter or receiver circuit, or even a microwave signal processor.
In parallel, we are looking to alternative architectures and tuning mechanisms that will allow us to eliminate the heaters we currently use for the tunable couplers and phase shifters. These are very power-hungry. One promising alternative approach is the integration of liquid crystals on the surface of the silicon chip, or micro-electromechanical actuators (MEMS)
Even when we are only starting to use our second-generation chip, we are already planning the design and fabrication of the next generation chip, where we intend to scale up the complexity and look into new circuit architectures. These architectures implemented in silicon photonics, with power-efficient tuners, electronic drivers, control algorithms and programming strategies, form complete technology stack. This way, we are laying the foundation for an ecosystem that will enable a future with off-the-shelf multifunctional programmable PICs.

The ecosystem for programmable PICs
The ecosystem for programmable PICs

Other people involved:

Related Research Projects

PhD thesises


    International Journals

  1. H. Sattari, A.Y. Takabayashi, Y. Zhang, P. Verheyen, W. Bogaerts, N. Quack, Compact suspended Silicon Photonic directional coupler, Optics Letters, 45(11), p.2997-3000 doi:10.1364/OL.394470 (2020)  Download this Publication (1MB).
  2. X. Chen, P. Stroobant, M. Pickavet, W. Bogaerts, Graph Representations for Programmable Photonic Circuits, IEEE Journal of Lightwave Technology, 38(15), p.4009-4018 doi:10.1109/JLT.2020.2984990 (2020)  Download this Publication (3.6MB).
  3. W. Bogaerts, A. Rahim, Programmable Photonics: An Opportunity for an Accessible Large-Volume PIC Ecosystem, IEEE Journal on Selected Topics in Quantum Electronics (invited), 26(5), p.8302517 doi:10.1109/JSTQE.2020.2982980 (2020)  Download this Publication (4.5MB).
  4. A. Ribeiro, S. Declercq, U. Khan, M. Wang, L. Van Iseghem, W. Bogaerts, Column-row addressing of thermo-optic phase shifters for controlling large silicon photonic circuits, IEEE Journal on Selected Topics in Quantum Electronics, 26(5), p.6100708 (8 pages) doi:10.1109/JSTQE.2020.2975669 (2020)  Download this Publication (3.3MB).
  5. M. Wang, A. Ribeiro, Y. Xing, W. Bogaerts, Tolerant, Broadband Tunable 2x2 Coupler Circuit, Optics Express, 28(4), p.5555-5566 doi:10.1364/OE.384018 (2020)  Download this Publication (3MB).
  6. N. Quack, H. Sattari, A.Y. Takabayashi, Y. Zhang, P. Verheyen, W. Bogaerts, P. Edinger, C. Errando-Herranz, K.B Gylfason, MEMS-enabled Silicon Photonic Integrated Devices and Circuits, Journal of Quantum Electronics (invited), 56(1), p.8400210 doi:10.1109/JQE.2019.2946841 (2020)  Download this Publication (3.6MB).
  7. I. Zand, W. Bogaerts, Effects of Coupling and Phase Imperfections in Programmable Photonic Hexagonal Waveguide Meshes, Photonics Research, 8(2), p.211-218 doi:10.1364/PRJ.376227 (2020)  Download this Publication (2.1MB).
  8. A. Li, W. Bogaerts, Reconfigurable nonlinear nonreciprocal transmission in a silicon photonic integrated circuit, Optica, 7(1), p.7-14 doi:10.1364/OPTICA.7.000007 (2020)  Download this Publication (3.4MB).
  9. H. Deng, W. Bogaerts, Pure phase modulation based on a silicon plasma dispersion modulator, Optics Express, 27(19), p.27191-27201 doi:10.1364/OE.27.027191 (2019)  Download this Publication (8.3MB).
  10. A. Li, W. Bogaerts, Using backscattering and backcoupling in silicon ring resonators as a new degree of design freedom, Lasers & Photonics Reviews, p.1800244 (18 pages) doi:10.1002/lpor.201800244 (2019)  Download this Publication (3.5MB).
  11. F. Laporte, J. Dambre, P. Bienstman, Highly parallel simulation and optimization of photonic circuits in time and frequency domain based on the deep-learning framework PyTorch, Scientific Reports, 9(1), p.5918 doi:10.1038/s41598-019-42408-2 (2019)  Download this Publication (1.3MB).
  12. Amir H. Safavi-Naeini, D. Van Thourhout, R. Baets, R. Van Laer, Controlling phonons and photons at the wavelength scale: integrated photonics meets integrated phononics, Optica (invited), 6(2), p.213 doi:10.1364/OPTICA.6.000213 (2019)  Download this Publication (2.2MB).
  13. A. Li, W. Bogaerts, Backcoupling manipulation in silicon ring resonators, Photonics Research, 6(6), p.620-629 doi:10.1364/PRJ.6.000620 (2018)  Download this Publication (2.6MB).
  14. A. Ribeiro, W. Bogaerts, Digitally controlled multiplexed silicon photonics phase shifter using heaters with integrated diodes, Optics Express, 25, doi:10.1364/OE.25.029778 (2017)  Download this Publication (4.1MB).
  15. A. Li, W. Bogaerts, An actively controlled silicon ring resonator with a fully tunable Fano Resonance, APL Photonics, 2(9), p.1-5 doi:10.1063/1.5000514 (2017)  Download this Publication (9.8MB).
  16. A. Li, W. Bogaerts, Fundamental Suppression of Backscattering in Silicon Microrings, Optics Express, 25(3), p.2092-2099 doi:10.1364/OE.25.002092 (2017)  Download this Publication (2.5MB).
  17. A. Ribeiro, A. Ruocco, L. Van Acker, W. Bogaerts, Demonstration of a 4x4-port universal linear circuit, Optica, 3(12), p.1348-1357 doi:10.1364/OPTICA.3.001348 (2016)  Download this Publication (2MB).
      International Conferences

    1. W. Bogaerts, P. Edinger, A.Y. Takabayashi, I. Zand, X. Chen, H. Sattari, P. Verheyen, M. Jezzini, G. Talli, S. Kumar, M. Garcia-Porcel, A. Ribeiro, G. Jo, N. Quack, K. Gylfason, F. Niklaus, U. Khan, Building Large-Scale Programmable PhotonicCircuits Using Silicon Photonics MEMS, OSA Advanced Photonics Congress - Photonics in Switching and Computing (invited), Canada, p.PsTh1F.1 (2020).
    2. L. Van Iseghem, U. Khan, P. Edinger, C. Errando-Herranz, A.Y. Takabayashi, H. Sattari, K.B. Gylfason, N. Quack, J. Beeckman, W. Bogaerts, Liquid crystal phase shifter integrated in a silicon photonics platform, European Conference on Integrated Optics, p.1.3 (2020)  Download this Publication (1.8MB).
    3. W. Bogaerts, H. Sattari, P. Edinger, A. Takabayashi, I. Zand, X. Wang, A. Ribeiro, M. Jezzini, C. Errando-Herranz, G. Talli, C. Lerma Arce, S. Kumar, M. Garcia, P. Verheyen, B. Abasahl, F. Niklaus, N. Quack, K. Gylfason, P. O'Brien, U. Khan, MORPHIC: Programmable Photonic Circuits enabled by Silicon Photonic MEMS, SPIE Photonics West - OPTO (invited), 11285, United States, p.1128503 doi:10.1117/12.2540934 (2020)  Download this Publication (11.6MB).
    4. X. Chen, W. Bogaerts, Building Graph-based Programming Strategies for Reconfigurable Photonic Circuits, Annual Symposium of the IEEE Photonics Society Benelux Chapter, Netherlands, p.1-4 (2019).
    5. X. Guo, T. Yin, Y. Liu, B. Morrison, C. Cantaloube, W. Bogaerts, B. Eggleton, D. Marpaung, A. Casas Bedoya, All-Integrated Universal RF Photonic Spectral Shaper, Asia Communications and Photonics Conference (ACP), China, p.M4D.7 (postdeadline) (2019)  Download this Publication (1.9MB).
    6. I. Zand, B. Abasahl, W. Bogaerts, Intensity Spread Analysis of Programmable Photonic Circuits with Parasitics, IEEE Photonics Society Summer Topicals, United States, p.paper TuE2.2 doi:10.1109/PHOSST.2019.8794953 (2019)  Download this Publication (646KB).
    7. F. Laporte, J. Dambre, P. Bienstman, Photontorch: Simulation and Optimization of Large Photonic Circuits Using the Deep Learning Framework PyTorch, IEEE Photonics Society Summer Topicals, United States, p.paper WE1.2 doi:10.1109/phosst.2019.8794941 (2019)  Download this Publication (271KB).
    8. M. Wang, A. Ribeiro, Y. Xing, W. Bogaerts, Tolerant, Broadband Tunable 2x2 Coupler Circuit, IEEE Photonics Society Summer Topicals, United States, p.paper WE3.3 (2 pages) doi: 10.1109/PHOSST.2019.8794978 (2019)  Download this Publication (2.2MB).
    9. W. Bogaerts, D.A.B. Miller, J. Capmany, The New World of Programmable Photonics, IEEE Photonics Society Summer Topicals (invited), United States, p.ME1.1 doi:10.1109/PHOSST.2019.8795032 (2019)  Download this Publication (3.6MB).
    10. X. Chen, W. Bogaerts, A Graph-based Design and Programming Strategy for Reconfigurable Photonic Circuits, IEEE Photonics Society Summer Topical Meeting Series (SUM) , United States, p.paper ME2.2 (2 pages) doi:10.1109/PHOSST.2019.8795068 (2019)  Download this Publication (1.6MB).
    11. U. Khan, B. Abasahl, I. Zand, N. Quack, K. Gylfason, M. Jezzini, H. Y. Hwang, M. A. G. Porcel, C. Lerma Arce, S. Kumar, W. Bogaerts, Generic Platform for Silicon Photonics based on MEMS Reconfigurable Photonic Integrated Circuits, Photonics & Electromagnetics Research Symposium (PIERS) 2019 (invited), Italy, p.2271 (2019)  Download this Publication (557KB).
    12. A. Ribeiro, U. Khan, L. Van Iseghem, M. Wang, S. Declercq, W. Bogaerts, Driving and control techniques for large scale programmable photonics circuits, PhotonIcs & Electromagnetics Research Symposium (PIERS) (invited), Italy, p.2568 (2019)  Download this Publication (860KB).
    13. H. Deng, W. Bogaerts, Configurable Modulator for Pure Phase Modulation, Photonics North, Canada, p. PS-87  doi:10.1109/PN.2019.8819529 (2019)  Download this Publication (75KB).
    14. B. Abasahl, W. Bogaerts, Evaluation of Stability of Silicon-Photonics-Based Optical Switch Network Architectures against Parasitic Errors in Switch Elements, 21st European Conference on Integratred Optics (ECIO 2019), Belgium, p.Po1.1 (2019)  Download this Publication (925KB).
    15. N. Quack, H. Sattari, A.Y. Takabayashi, Y. Zhang, P. Edinger, C. Errando-Herranz, K. Gylfason, X. Wang, F. Niklaus, M. A. Jezzini, H.Y. Hwang, P. O'Brien, M.A.G. Porcel, C. Lerma Arce, S. Kumar, B. Abasahl, P. Verheyen, W. Bogaerts, Silicon Photonic MEMS: Exploiting Mechanics at the Nanoscale to Enhance Photonic Integrated Circuits, Optical Fiber Communication Conference (invited), United States, p.M2D.3 doi:10.1364/ofc.2019.m2d.3 (2019)  Download this Publication (447KB).
    16. B. Abasahl, I. Zand, C. Lerma Arce, S. Kumar, N. Quack, M. A. Jezzini, H. Y. Hwang, K. Gylfason, M. A. G. Porcel, W. Bogaerts, Towards Low-Power Reconfigurable Photonic ICs Based on MEMS Technology, Australian Institute of Physics Congress (invited), Australia, (2018).
    17. I. Zand, B. Abasahl, U. Khan, W. Bogaerts, Controlling parasitics in linear optical processors, Proceedings of the 23rd Annual Symposium of the IEEE Photonics Benelux Chapter, Belgium, p.152-155 (2018)  Download this Publication (894KB).
    18. L. Van Iseghem, U. Khan, Jeroen Beeckman, W. Bogaerts, On-chip beam shaping using lateral leakage, Proceedings of the 23rd Annual Symposium of the IEEE Photonics Benelux Chapter, Belgium, p.136-139 (2018)  Download this Publication (711KB).
    19. U. Khan, W. Bogaerts, N. Quack, K.B. Gylfason , P. Verheyen, P. O'Brien, C.L. Arce, M. Garcia, The MORPHIC Project: Enabling large scale programmable photonic circuits using MEMS, Photonics Ireland Conference 2018 (invited), Ireland, p.We.J1.3 (2018)  Download this Publication (859KB).
    20. W. Bogaerts, Large-scale Programmable Silicon Photonics, European Conference on Integrated Optics (invited), 2018, Spain, p.We.3.A.1 (2018)  Download this Publication (318KB).
    21. A. Ribeiro, U. Khan, W. Bogaerts, Matrix Addressing Silicon Photonics Phase Shifters using Heaters with Integrated Diodes, European Conference on Integrated Optics (ECIO, Spain, p.We.3.A.5. (2018)  Download this Publication (250KB).
    22. W. Bogaerts, Programmable photonic ICs: making optical devices more versatile, PIC International Conference (invited), Belgium, (2018)  Download this Publication (6.6MB).
    23. A. Ribeiro, W. Bogaerts, Thermo-optical Phase Shifter with Integrated Diodes for Multiplexed Control, The Optical Fiber Communication Conference (OFC), United States, p.Th32.A.4 doi:10.1364/ofc.2018.th2a.4 (2018)  Download this Publication (3.8MB).
    24. A. Li, W. Bogaerts, A novel approach to create a tunable Fano resonance with an extinction ratio over 40dB, IEEE International Conference on Group IV Photonics, Germany, p.27-28 doi:10.1109/GROUP4.2017.8082179 (2017)  Download this Publication (1.4MB).
    25. A. Li, Y. Xing, W. Bogaerts, An integrated tunable reflector, European Conference on Integrated Optics (ECIO, Netherlands, p.paper W3.1 (2017)  Download this Publication (971KB).
    26. W. Bogaerts, Scaling Up Silicon Photonic Circuits: Where Are the Challenges?, International Workshop on Optical/Photonic Interconnects for Computing Systems (OPTICS Workshop) (invited), 3, Switzerland, (2017)  Download this Publication (275KB).
    27. A. Ribeiro, K. Miura, T. Spuesens, W. Bogaerts, Phase shift control with active feedback, Proceedings Symposium IEEE Photonics Society Benelux, Belgium, p.291-294 (2016)  Download this Publication (552KB).
    28. A. Ribeiro, A. Ruocco, L. Van Acker, W. Bogaerts, Demonstration of a4x4-port self-configuring universal linear optical component, Progress In Electromagnetics Research Symposium (invited), China, p.3372-3375 doi:10.1109/piers.2016.7735319 (2016)  Download this Publication (551KB).
    29. A. Ribeiro, K. Miura, T. Spuesens, W. Bogaerts, On-chip Differential Phase Monitoring with Balanced Photodiodes, IEEE International Conference on Group IV Photonics, China, p.80-81 doi:10.1109/GROUP4.2016.7739079 (2016)  Download this Publication (3.9MB).
    30. W. Bogaerts, Challenges for Designing Large-scale Integrated Photonics, European Conference on Integrated Optics (ECIO) / Workshop on Optical Waveguide Theory an Numerical Modeling (OWTNM) (invited), Poland, p.OWTNM-I-01 (2016)  Download this Publication (268KB).
    31. W. Bogaerts, Silicon Photonics: Designing for Complexity, HiPEAC Computing Systems Week (invited), Italy, (2015).
    32. A. Ribeiro, A. Ruocco, L. Van Acker, W. Bogaerts, Demonstration of a 4x4-port Universal Coupler, 12th International Conference on Group IV Photonics, Canada, p.PD5 (2015)  Download this Publication (1.1MB).
        National Conferences

      1. Mi Wang , Antonio Ribeiro, Yufei Xing, Wim Bogearts, Analysis of phase compensation method for the tunable coupler, accepted for publication in IEEE Photonics Scociety Benelux Annual Symposium,Netherlands,  (to be published).

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