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Monolithically integrated optical waveguide isolator

Research Area: III-V Semiconductor Photonic ICs

Main Researcher: Wouter Van Parys

An optical isolator is indispensable for the protection of a laser source from the optical feedback in a telecom link. A planar, waveguide version of this component is highly desirable as this would greatly reduce the cost and size of a laser diode package. Traditionally, research focuses on ferrimagnetic garnet material to realize non-reciprocity. Stand-alone isolators with good performance have been demonstrated but the integration with III-V semiconductor hosts remains an issue that is difficult to solve.
We are studying a TM-mode isolator configuration which holds the promise of monolithic integration with III-V active devices.

Figure 1. Schematic lay-out and operation principle of the TM-mode optical waveguide isolator.
Figure 1. Schematic lay-out and operation principle of the TM-mode optical waveguide isolator.

The amplifying waveguide isolator is a semiconductor optical amplifier (SOA) topped with a laterally magnetized (magnetization M <> 0) ferromagnetic metal film, which is separated from the amplifying core by only a very narrow cladding layer. The magneto-optic Kerr effect causes a non-recipocal complex shift of the effective index of TM-polarized guided modes. Electrical pumping of the SOA with the ferromagnetic metal as the electrical contact compensates the loss in the forward propagation direction. The result is a device, which, being transparent in one propagation direction while providing net loss in the other direction, is isolating. Figure 1 illustrates the lay-out and the operation principle of the isolator. As this device basically has the same structure as the laser it is to be integrated with, monolithic integration is straightforward. Furthermore, as the ferromagnetic film can easily be sputter-deposited on III-V semiconductor layers, the optical waveguide isolator can be fabricated using standard InP-SOA processing techniques.

Figure 2. TM mode nonreciprocal loss shift at 1290nm. 3.77dB is equivalent to an isolation ratio of 99dB/cm.
Figure 2. TM mode nonreciprocal loss shift at 1290nm. 3.77dB is equivalent to an isolation ratio of 99dB/cm.

In 2003 we demonstrated this isolator concept for the first time worldwide. Since then, we constantly improved the performance of this component. Todays device is built up of an AlGaInAs/InP tensile strained multi quantum well waveguide covered with a Co50Fe50 metal film. We designed the thickness of the InP cladding layer to combine maximal optical isolation and minimal bias current needed for forward transparency. Figure 2 illustrates the demonstration of 3.77dB optical isolation, measured on a device of 380um length.

Other people involved:

Related Research Projects

PhD thesises

Publications

    International Journals

  1. W. Van Parys, D. Van Thourhout, R. Baets, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, L. Lagae, Amplifying Waveguide Optical Isolator With an Integrated Electromagnet, IEEE Photonics Technology Letters, 19(24), p.1949-1951 doi:10.1109/lpt.2007.909634 (2007)  Download this Publication (275KB).
  2. W. Van Parys, M. Vanwolleghem, D. Van Thourhout, R. Baets, F. Lelarge, B. Thedrez, L. Lagae, Study of a Magnetooptic Contact for an Amplifying Waveguide Optical Isolator, Photonics Technology Letters, 19(9), p.659-661 doi:10.1109/lpt.2007.894965 (2007)  Download this Publication (267KB).
  3. M. Vanwolleghem, W. Van Parys, P. Gogol, P. Beauvillain, R. Baets, Design and optimization of a monolithically integratable InP-based optical waveguide isolator, JOSA B, 24(1), p.94-105 doi:10.1364/josab.24.000094 (2007)  Download this Publication (307KB).
  4. W. Van Parys, B. Moeyersoon, D. Van Thourhout, R. Baets, M. Vanwolleghem, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, R. Vanheertum, L. Lagae, Transverse magnetic mode nonreciprocal propagation in an amplifying AlGaInAs/InP optical waveguide isolator, Applied Physics Letters, 88, p.071115 doi:10.1063/1.2174106 (2006)  Download this Publication (196KB).
  5. F. Lelarge, B. Dagens, C. Cuisin, O. Le Gouezigou, G. Patriarche, W. Van Parys, M. Vanwolleghem, R. Baets, J.L. Gentner, GSMBE growth of GaInAsP/InP 1.3 ìm-TM-lasers for monolithic integration with optical waveguide isolator, Journal of Crystal Growth, 278(1-4), p.709-713 doi:10.1016/j.jcrysgro.2004.12.154 (2005)  Download this Publication (298KB).
  6. K. Postava, M. Vanwolleghem, D. Van Thourhout, R. Baets, S. Visnovský, P. Beauvillain, J. Pistora, Modeling of a novel InP-based monolithically integrated magneto-optical waveguide isolator , JOSA B, 22(1), p.261-273 doi:10.1364/josab.22.000261 (2005)  Download this Publication (4.1MB).
  7. M. Vanwolleghem, W. Van Parys, D. Van Thourhout, R. Baets, F. Lelarge, O. Gauthier-Lafaye, B. Thedrez, R. Wirix-Speetjens, L. Lagae, Experimental demonstration of nonreciprocal amplified spontaneous emission in a CoFe clad semiconductor optical amplifier for use as an integrated optical isolator, Applied Physics Letters, 85(18), p.3980-3982 doi:10.1063/1.1811802 (2004).
      International Conferences

    1. W. Van Parys, D. Van Thourhout, R. Baets, Amplifying Waveguide Optical Isolator with an Integrated Electromagnet, IEEE/LEOS Symposium Benelux Chapter, 2007, Belgium, p.7-10 (2007)  Download this Publication (101KB).
    2. H. Shimizu, W. Van Parys, R. Baets, Y. Nakano, Characterization of nonlinear nonreciprocal propagation in semiconductor amplifying waveguide optical isolators, 68th Autumn Meeting of the Japan Society of Applied Physics, Japan, p.4p-P3-21 (2007)  Download this Publication (290KB).
    3. W. Van Parys, D. Van Thourhout, R. Baets, Optimization of a TM-mode Amplifying Waveguide, IEEE/LEOS Benelux Annual Workshop 2007, Netherlands, p.23-24 (2007)  Download this Publication (74KB).
    4. W. Van Parys, D. Van Thourhout, R. Baets, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, L. Lagae, Amplifying Waveguide Optical Isolator with Integrated Electromagnet, ECIO 2007, Denmark, p.ThA5 (2007)  Download this Publication (255KB).
    5. W. Van Parys, D. Van Thourhout, R. Baets, B. Dagens, L. Lagae, Transparent amplifying waveguide optical isolator, ePIXnet Winterschool 2007, Switzerland, p.93 (2007)  Download this Publication (119KB).
    6. W. Van Parys, D. Van Thourhout, R. Baets, M. Vanwolleghem, B. Thedrez, F. Lelarge, L. Lagae, R. Wirix-Speetjens, Magneto-optic Contact for Application in an Amplifying Waveguide Optical Isolator, 2006 IEEE LEOS Annual Meeting, Canada, p.679-680 doi:10.1109/leos.2006.278895 (2006)  Download this Publication (459KB).
    7. W. Van Parys, D. Van Thourhout, R. Baets, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, R. Vanheertum, L. Lagae, TM-mode AlGaInAs/InP Amplifying Waveguide Optical Isolator with 12.7dB Isolation, Integrated Photonics Research and Applications, United States, p.ITuG3 doi:10.1364/ipra.2006.itug3 (2006)  Download this Publication (141KB).
    8. W. Van Parys, D. Van Thourhout, R. Baets, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, R. Vanheertum, L. Lagae, 11.4dB Isolation on an Amplifying AlGaInAs/InP Optical Waveguide Isolator, OFC 2006, United States, p.OFA2 doi:10.1109/ofc.2006.215932 (2006)  Download this Publication (252KB).
    9. W. Van Parys, D. Van Thourhout, R. Baets, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, R. Vanheertum, L. Lagae, Amplifying AlGaInAs/InP Waveguide Optical Isolator with 99dB/cm Non-reciprocal Propagation, IEEE/LEOS Symposium Benelux Chapter, 2005, Belgium, p.83-86 (2005)  Download this Publication (130KB).
    10. M. Vanwolleghem, W. Van Parys, P. Gogol, R. Baets, P. Beauvillain, Optimisation d un isolateur magneto-optique integre pour diode laser a la longeur d onde de 1.3um, Horizons de l Optique 2005, France, p.135-136 (2005)  Download this Publication (63KB).
    11. M. Vanwolleghem, W. Van Parys, P. Gogol, R. Baets, P. Beauvillain, Optimization of a monolithically integrated ferromagnetic-metal-clad InP-based optical waveguide isolator, 10ieme colloque Louis Neel, France, p.VI.35 (2005)  Download this Publication (90KB).
    12. L. Lagae, W. Van Parys, B. Moeyersoon, D. Van Thourhout, R. Baets, R. Vanheertum, B. Dagens, J. Decobert, O. Le Gouezigou, D. Make, Magneto-optical waveguide isolator with 104 dB/cm non-reciprocal propagation, Moscow International Symposium on Magnetism, Russia, p.114 (2005)  Download this Publication (136KB).
    13. W. Van Parys, R. Baets, InP-based optical waveguide isolator, IEEE/LEOS Benelux Annual Workshop 2005, Netherlands, p.4 (2005)  Download this Publication (70KB).
    14. W. Van Parys, M. Vanwolleghem, D. Van Thourhout, R. Baets, J. Decobert, B. Dagens, B. Thedrez, L. Lagae, R. Wirix-Speetjens, Demonstration of 81dB/cm isolation on an InP-based optical waveguide isolator, ECIO 2005, France, p.33-36 (2005)  Download this Publication (84KB).
    15. W. Van Parys, M. Vanwolleghem, D. Van Thourhout, R. Baets, J. Decobert, B. Dagens, B. Thedrez, R. Wirix-Speetjens, L. Lagae, InP-Based Monolithically Integrated Optical Waveguide Isolator with 32 dB/cm Isolation, 2004 IEEE LEOS Annual Meeting, Puerto Rico, p.386-387 (2004)  Download this Publication (138KB).
    16. W. Van Parys, M. Vanwolleghem, D. Van Thourhout, R. Baets, R. Wirix-Speetjens, L. Lagae, B. Thedrez, F. Lelarge, O. Gauthier-Lafaye, Experimental Verification of a Novel Integrated Optical Isolator Concept , Bianisotropics 2004, Belgium, p.224-227 (2004)  Download this Publication (73KB).
    17. F. Lelarge, B. Dagens, C. Cuisin, O. Le Gouezigou, G. Patriarche, W. Van Parys, M. Vanwolleghem, R. Baets, GSMBE growth for 1.3um-TM-lasers for monolithic integration with optical waveguide isolator, 13th International Conference on Molecular Beam Epitaxy (IC-MBE), United Kingdom, p.ThA2.2 (2004).
    18. W. Van Parys, Demonstration of a Novel Integrated Isolator Concept, IEEE/LEOS Benelux Chapter Workshop on Photonic Materials and Technology, Netherlands, p.12 (2004)  Download this Publication (48KB).
    19. M. Vanwolleghem, W. Van Parys, D. Van Thourhout, R. Baets, O. Gauthier-Lafaye, F. Lelarge, B. Thedrez, R. Wirix-Speetjens, J. De Boeck, First Experimental Demonstration of a monolithically integrated InP-based waveguide isolator, OFC 2004, United States, p.TuE6 (2004)  Download this Publication (8.1MB).
    20. M. Vanwolleghem, W. Van Parys, D. Van Thourhout, R. Baets, F. Lelarge, O. Gauthier-Lafaye, B. Thedrez, R. Wirix-Speetjens, J. De Boeck, Experimental verification of a novel integrated isolator concept, ECOC-IOOC, 6, Italy, p.78-79 (2003).
    21. M. Vanwolleghem, W. Van Parys, S. Verstuyft, R. Wirix-Speetjens, L. Lagae, J. De Boeck, R. Baets, Ferromagnetic-metal-based InGaAs(P)/InP optical waveguide isolator: electrical and magneto-optical characterisation, 2002 Annual Symposium of the IEEE/LEOS Benelux Chapter, Netherlands, p.282-285 (2002).
    22. M. Vanwolleghem, M. Leys, J. Das, L. Lagae, J. De Boeck, P. Van Daele, R. Baets, Ferromagnetic-metal-based InGaAs(P)/InP optical waveguide isolator : steps towards experimental validation, LEOS 2001, United States, p.294-295 doi:10.1109/leos.2001.969291 (2001).
        National Conferences

      1. W. Van Parys, D. Van Thourhout, R. Baets, InP-based Monolithically Integratable Optical Waveguide Isolator, 5e UGent-FTW Doctoraatssymposium, Belgium, (2004)  Download this Publication (77KB).
      2. M. Vanwolleghem, R. Baets, A Novel type of integrable non-reciprocal photonic waveguides devices, 1ste doctoraatssympoisum FTW, Belgium, (2000).

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