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2D grating fibre coupler used as polarization splitter

Research Area: III-V Semiconductor Photonic ICs

Main Researcher: Dirk Taillaert

To solve the coupling problem between nanophotonic waveguides and optical fibre, we are developing a vertical fibre coupler. The coupler and nanophotonic components in general are strongly polarization dependent. Optical communication systems however require polarization independent operation. Therefore we are also doing research on 2D-grating couplers.
A 2D-grating coupler can be used as a polarization splitter : the grating splits the orthogonal components of the light coming from a fiber into two different waveguides. In these waveguides however the polarization is the same. The coupling of light from a fiber to each waveguide will depend on the polarization of the incoming light, but the total coupling efficiency from fibre to both waveguides together will be polarization independent.

Using this fibre coupler, a polarization diversity scheme can be easily used to make photonic circuits that are polarization independent, although the waveguides used (e.g. photonic crystal waveguides) are strongly polarization dependent. It should be noted that our approach does NOT need a polarization rotator. This is a major advantage because polarization rotators are difficult to integrate on a chip.

polarization diversity scheme
polarization diversity scheme

We have demonstrated 20% coupling efficiency and a good extinction ratio (>20dB) between the two channels with the structure shown above. The structures were fabricated on commercially available SOI wafer (220nm Si / 1000nm SiO2 / Si substrate). Further work is in progress to improve the efficiency.

Other people involved:

Related Research Projects

PhD thesises



    International Journals

  1. S. Pathak, M. Vanslembrouck, P. Dumon, D. Van Thourhout, W. Bogaerts, Compact SOI-Based Polarization Diversity Wavelength De-multiplexer Circuit Using Two Symmetric AWGs, Optics Express, 20(26), p.B493-B500 doi:10.1364/oe.20.00b493 (2012)  Download this Publication (5.5MB).
  2. R. Halir, D. Vermeulen, G. Roelkens, Reducing polarization dependent loss of silicon-on-insulator fiber to chip grating couplers, IEEE Photonics Technology Letters, 22(6), p.389-391 doi:10.1109/lpt.2009.2039869 (2010)  Download this Publication (312KB).
  3. F. Van Laere, T. Stomeo, C. Cambournac, M. Ayre, R. Brenot, H. Benisty, G. Roelkens, T. F. Krauss, D. Van Thourhout, R. Baets, Nanophotonic polarization diversity demultiplexer chip, Journal of Lightwave Technology, 27(4), p.417-425 doi:10.1109/jlt.2008.929414 (2009)  Download this Publication (1.6MB).
  4. F. Van Laere, T. Stomeo, D. Taillaert, G. Roelkens, D. Van Thourhout, T.F. Krauss, R. Baets, Efficient Polarization Diversity Grating Couplers in Bonded InP-membrane, IEEE Photonics Technology Letters, 20(4), p.318-320 doi:10.1109/lpt.2007.915587 (2008)  Download this Publication (276KB).
  5. W. Bogaerts, D. Taillaert, P. Dumon, D. Van Thourhout, R. Baets, A polarization-diversity wavelength duplexer circuit in silicon-on-insulator photonic wires, Optics Express, 15(4), p.1567-1578  doi:10.1364/oe.15.001567 (2007)  Download this Publication (1MB).
  6. D. Taillaert, P. Bienstman, R. Baets, Compact efficient broadband grating coupler for silicon-on-insulator waveguides , Optics Letters, 29(23), p.2749-2751 doi:10.1364/ol.29.002749 (2004)  Download this Publication (280KB).
  7. V.S. Volkov, S.L. Bozhevolnyi, D. Taillaert, Near-field imaging of light diffraction out of slab waveguides, Laser Physics Letters, 1(6), p.311-316 doi:10.1002/lapl.200410072 (2004).
  8. D. Taillaert, H. Chong, P. Borel, L. Frandsen, R.M. De La Rue, R. Baets, A compact two-dimensional grating coupler used as a polarization splitter, IEEE Photonics Technology Letters, 15(9), p.1249-1251 doi:10.1109/lpt.2003.816671 (2003)  Download this Publication (519KB).
  9. D. Taillaert, W. Bogaerts, P. Bienstman, T.F. Krauss, P. Van Daele, I. Moerman, S. Verstuyft, K. De Mesel, R. Baets, An Out-of-Plane Grating Coupler for Efficient Butt-Coupling Between Compact Planar Waveguides and Single-Mode Fibers, IEEE Journal of Quantum Electronics, 38(7), p.949-955 doi:10.1109/jqe.2002.1017613 (2002)  Download this Publication (612KB).
      International Conferences

    1. S. Pathak, M. Vanslembrouck, P. Dumon, D. Van Thourhout, W. Bogaerts, Compact SOI-Based Polarization Diversity Wavelength De-multiplexer Circuit Using Two Symmetric AWGs., 38th European Conference and Exhibition on Optical Communication (ECOC 2012), Netherlands, p.paper Tu.4.E.4 doi:10.1364/eceoc.2012.tu.4.e.4 (2012)  Download this Publication (1.1MB).
    2. D. Vermeulen, S. Selvaraja, R. Halir, W. Bogaerts, D. Van Thourhout, G. Roelkens, Photonic Integrated Circuits on SOI for Optical Fiber Communication Applications, 15th Annual Symposium of the IEEE Photonics Benelux Chapter, Netherlands, (2010)  Download this Publication (229KB).
    3. W. Bogaerts, P. Dumon, S. Selvaraja, D. Van Thourhout, R. Baets, Silicon nanophotonic waveguide components, Silicon Nanoelectronics and Photonics (SiNEP) 2009 (invited), Spain, p.33-34 (2009)  Download this Publication (381KB).
    4. D. Vermeulen, G. Roelkens, D. Van Thourhout, R. Baets, SOI 1D and 2D photonic crystal structures for polarization independent fiber-to-chip coupling and duplexing operation, The 8th International Photonic & Electromagnetic Crystal Structures Meeting (PECS), Australia, (2009)  Download this Publication (227KB).
    5. F. Van Laere, W. Bogaerts, P. Dumon, G. Roelkens, D. Van Thourhout, R. Baets, Focusing polarization diversity gratings for Silicon-on-Insulator integrated circuits, Group IV Photonics, Italy, p.ThB3 doi:10.1109/group4.2008.4638145 (2008)  Download this Publication (429KB).
    6. F. Van Laere, T. Stomeo, D. Taillaert, D. Van Thourhout, T. F. Krauss, R. Baets, Polarization diversity grating couplers in bonded InP-membranes, PECS VII, United States, (2007)  Download this Publication (57KB).
    7. R. Baets, W. Bogaerts, D. Taillaert, P. Dumon, D. Van Thourhout, SOI Photonic Wire Based Components with Compact and Efficient Fiber Couplers , Optical Fiber Communications (invited), United States, p.OWG3 doi:10.1109/ofc.2007.4348871 (2007)  Download this Publication (594KB).
    8. W. Bogaerts, D. Taillaert, P. Dumon, E. Pluk, D. Van Thourhout, R. Baets, A Compact Polarization-Independent Wavelength Duplexer Using a Polarization-Diversity SOI Photonic Wire Circuit , Optical Fiber Communications, United States, p.OTuM2 doi:10.1109/ofc.2007.4348826 (2007)  Download this Publication (225KB).
    9. F. Van Laere, G. Roelkens, J. Schrauwen, D. Taillaert, P. Dumon, W. Bogaerts, D. Van Thourhout, R. Baets, Compact grating couplers between optical fibers and Silicon-on-Insulator photonic wire waveguides with 69% coupling efficiency, OFC 2006, United States, p.PDP15 doi:10.1109/ofc.2006.216051 (2006)  Download this Publication (639KB).
    10. W. Bogaerts, P. Dumon, J. Wouters, P. Jaenen, S. Beckx, V. Wiaux, D. Van Thourhout, D. Taillaert, B. Luyssaert, R. Baets, Silicon-on-Insulator Nanophotonics, SPIE Optics and Optoelectronics (invited), 5956, Poland, p.5956R-1-15 (2005)  Download this Publication (758KB).
    11. R. Baets, D. Van Thourhout, G. Morthier, W. Bogaerts, L. Vanholme, Silicon-on-insulator based high index contrast waveguide devices: research in europe, 11th Microoptics Conference (MOC) (invited), Japan, p.E2, Session C ( 4 pages) (2005)  Download this Publication (303KB).
    12. R. Baets, P. Dumon, W. Bogaerts, G. Roelkens, D. Taillaert, B. Luyssaert, G.R.A. Priem, G. Morthier, P. Bienstman, D. Van Thourhout, Silicon-on-insulator based Nano-photonics: Why, How, What for?, Group IV Photonics (invited), Belgium, p.168-170 (2005)  Download this Publication (172KB).
    13. D. Taillaert, R. Baets, P. Dumon, W. Bogaerts, D. Van Thourhout, B. Luyssaert, V. Wiaux, S. Beckx, J. Wouters, Silicon-on-Insulator Platform for Integrated Wavelength-Selective Components, Workshop on Fibres and Optical Passive Components (invited), Italy, doi:10.1109/wfopc.2005.1462110 (2005)  Download this Publication (1MB).
    14. R. Baets, P. Dumon, W. Bogaerts, D. Van Thourhout, B. Luyssaert, D. Taillaert, P. Bienstman, V. Wiaux, S. Beckx, J. Wouters, Silicon-on-insulator platform for WDM-components, Proceedings of the 2004 IEEE LEOS Annual Meeting (proceedings available on CD-Rom) (invited), Puerto Rico, p.741-742 doi:10.1109/leos.2004.1363452 (2004)  Download this Publication (130KB).
    15. R. Baets, Photonic Crystal Research in IST, European Conference on Optical Communication (ECOC) 2004 (invited), 5(Symposia), Sweden, p.80-82 (2004)  Download this Publication (75KB).
    16. D. Taillaert, W. Bogaerts, R. Baets, Efficient coupling between submicron SOI-waveguides and single-mode fibers, IEEE/Leos Benelux Annual Symposium 2003, Netherlands, p.289-292 (2003).
    17. D. Taillaert, R. Baets, H. Chong, R.M. De La Rue, P. Borel, L. Frandsen, A compact two-dimensional Grating Coupler used as a polarisation splitter, European Conference on Integrated Optics (ECIO), Czech Republic, p.PD:5-8 (2003)  Download this Publication (1.2MB).
    18. D. Taillaert, W. Bogaerts, P. Bienstman, R. Baets, Out-of-plane fiber coupler for coupling to high-index-contrast waveguides, PECS-IV, United States, p.155 (2002)  Download this Publication (114KB).
    19. R. Baets, Managing out-of-plane coupling 2D crystals, Workshop and EOS Topical meeting -Two Dimensional Photonic Crystals (invited), Switzerland, (2002).
    20. R. Baets, Towards nanophotonic integrated circuits: the challenges, Conference on Optoelectronics and Optical Communications (COOC 2002) (invited), 9(1), p.3-4 (2002).
        National Conferences

      1. F. Van Laere, T. Stomeo, D. Van Thourhout, T. F. Krauss, R. Baets, Efficient Polarization Independent Optical Link in Bonded InP-membrane, 8th FirW PhD Symposium, Interactive poster session, paper nr. 38 (proceedings available on CD-ROM), Belgium, (2007)  Download this Publication (471KB).
      2. D. Taillaert, R. Baets, A grating-coupler interface between photonic integrated circuits and optical fibers, 3rd FTW PHD Symposium, Interactive poster session, paper nr. 64 (proceedings available on CD-Rom) , Belgium, (2002).

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