Ultra-thin silicon/electro-optic polymer hybrid waveguide modulators

Ultra-thin silicon and electro-optic (EO) polymer hybrid waveguide modulators have been designed and fabricated. The waveguide consists of a silicon core with a thickness of 30 nm and a width of 2 μm. The cladding is an EO polymer. Optical mode calculation reveals that 55% of the optical field around the silicon extends into the EO polymer in the TE mode. A Mach-Zehnder interferometer (MZI) modulator was prepared using common coplanar electrodes. The measured half-wave voltage of the MZI with 7 μm spacing and 1.3 cm long electrodes is 4.6 V at 1550 nm. The evaluated EO coefficient is 70 pm/V, which is comparable to that of the bulk EO polymer film. Using ultra-thin silicon is beneficial in order to reduce the side-wall scattering loss, yielding a propagation loss of 4.0 dB/cm. We also investigated a mode converter which couples light from the hybrid EO waveguide into a strip silicon waveguide. The calculation indicates that the coupling loss between these two devices is small enough to exploit the potential fusion of a hybrid EO polymer modulator together with a silicon micro-photonics device.

[1]  W Freude,et al.  Reduced propagation loss in silicon strip and slot waveguides coated by atomic layer deposition. , 2011, Optics express.

[2]  Larry R. Dalton,et al.  Nonlinear polymer-clad silicon slot waveguide modulator with a half wave voltage of 0.25 V , 2008 .

[3]  S. Yokoyama,et al.  Electro‐optic polymer/titanium dioxide hybrid core ring resonator modulators , 2013 .

[4]  T. Hashimoto,et al.  Low-Loss Y-Branch Waveguides Designed by Wavefront Matching Method , 2009, Journal of Lightwave Technology.

[5]  S Wabnitz,et al.  Second-harmonic generation in silicon waveguides strained by silicon nitride. , 2012, Nature materials.

[6]  Raluca Dinu,et al.  Silicon-Organic Hybrid Electro-Optical Devices , 2013, IEEE Journal of Selected Topics in Quantum Electronics.

[7]  Nasser Peyghambarian,et al.  A Silicon-Polymer Hybrid Modulator—Design, Simulation and Proof of Principle , 2013, Journal of Lightwave Technology.

[8]  W. Steier,et al.  Analysis and Demonstration of Mach–Zehnder Polymer Modulators Using In-Plane Coplanar Waveguide Structure , 2007, IEEE Journal of Quantum Electronics.

[9]  F. Payne,et al.  Radiation loss from planar waveguides with random wall imperfections , 1990 .

[10]  T. Baehr‐Jones,et al.  Silicon-polymer hybrid slot waveguide ring-resonator modulator. , 2011, Optics express.

[11]  W. Steier,et al.  Conductivity-dependency-free in-plane poling for Mach-Zehnder modulator with highly conductive electro-optic polymer , 2007 .

[12]  O. Hansen,et al.  Strained silicon as a new electro-optic material , 2006, Nature.

[13]  David J. Thomson,et al.  Silicon optical modulators , 2010 .

[14]  Isao Aoki,et al.  Nonlinear optical side-chain polymers post-functionalized with high-β chromophores exhibiting large electro-optic property , 2011 .

[15]  Roger Dangel,et al.  Polymer waveguides for electro-optical integration in data centers and high-performance computers. , 2015, Optics express.

[16]  M. Ozawa,et al.  A straightforward electro-optic polymer covered titanium dioxide strip line modulator with a low driving voltage , 2014 .

[17]  P. Dumon,et al.  Silicon microring resonators , 2012 .

[18]  D Hillerkuss,et al.  42.7 Gbit/s electro-optic modulator in silicon technology. , 2011, Optics express.

[19]  Wolfgang Freude,et al.  High-Speed, Low Drive-Voltage Silicon-Organic Hybrid Modulator Based on a Binary-Chromophore Electro-Optic Material , 2014, Journal of Lightwave Technology.

[20]  R. Soref,et al.  The Past, Present, and Future of Silicon Photonics , 2006, IEEE Journal of Selected Topics in Quantum Electronics.

[21]  Jingdong Luo,et al.  Highly Efficient Organic Electrooptic Materials and Their Hybrid Systems for Advanced Photonic Devices , 2013, IEEE Journal of Selected Topics in Quantum Electronics.