Tunable silicon photonics directional coupler driven by a transverse temperature gradient.

A compact directional coupler fabricated on a silicon photonic platform is presented, with a power-splitting ratio that can be tuned through a transverse temperature gradient induced by a laterally shifted integrated heater. The tuning mechanism exploits the thermally induced phase velocity mismatch between the coupled modes of the silicon waveguides. The positions of the integrated heater and the waveguide design are optimized to maximize the tuning range and to reduce electric power consumption. Asynchronous devices with an intrinsic phase mismatch are demonstrated to be more efficient, providing a tunable coupled power from 0.7 to 0.01 with 36 mW maximum power dissipation.

[1]  P. Yeh,et al.  Photonics : optical electronics in modern communications , 2006 .

[2]  O. Schwelb,et al.  Transmission, group delay, and dispersion in single-ring optical resonators and add/drop filters-a tutorial overview , 2004, Journal of Lightwave Technology.

[3]  S. Yegnanarayanan,et al.  Optimization of metallic microheaters for high-speed reconfigurable silicon photonics. , 2010, Optics express.

[4]  L. O'Faolain,et al.  Tunable Delay Lines in Silicon Photonics: Coupled Resonators and Photonic Crystals, a Comparison , 2010, IEEE Photonics Journal.

[5]  R. Schmidt,et al.  Switched directional couplers with alternating Δ Β , 1976 .

[6]  Kun-Yii Tu,et al.  Demonstration of a Tunable Microwave-Photonic Notch Filter Using Low-Loss Silicon Ring Resonators , 2009, Journal of Lightwave Technology.

[7]  Marc Sorel,et al.  Reconfigurable silicon filter with continuous bandwidth tunability. , 2012, Optics letters.

[8]  Ivo Rendina,et al.  Temperature dependence of the thermo-optic coefficient in crystalline silicon between room temperature and 550 K at the wavelength of 1523 nm , 1999 .

[9]  R. S. Guzzon,et al.  Programmable Photonic Lattice Filters in InGaAsP–InP , 2010, IEEE Photonics Technology Letters.

[10]  J. Leuthold,et al.  Multimode interference couplers with tunable power splitting ratios , 2001 .

[11]  Francesca Magno,et al.  Investigation of thermo-optic effect and multi-reflector tunable filter/multiplexer in SOI waveguides. , 2005, Optics express.

[12]  Michal Lipson,et al.  High bandwidth on-chip silicon photonic interleaver. , 2010, Optics express.

[13]  M. Lipson,et al.  CMOS compatible reconfigurable filter for high bandwidth non-blocking operation. , 2011, Optics express.