Compact and Polarization-Independent Variable Optical Attenuator Based on a Silicon Wire Waveguide with a Carrier Injection Structure

We developed a Si variable optical attenuator (VOA) with low-polarization-dependent loss (PDL). We designed the core dimensions to reduce PDL originating from free-carrier absorption. In the core dimensions, there is a big margin for which the PDL is less than 1 dB when attenuation is -20 dB. On the basis of calculations, we fabricated the Si VOAs and evaluated them. A fabricated Si VOA exhibited PDL of 0.2 dB due to free-carrier absorption when the attenuation was -20 dB. Moreover, we verified that the PDL is less than 1 dB in a wide range of core widths, it is tolerant to fabrication error.

[1]  Kenichi Saito,et al.  EB-X3: New electron-beam x-ray mask writer , 1999 .

[2]  X.M. Zhang,et al.  Linear MEMS variable optical attenuator using reflective elliptical mirror , 2005, IEEE Photonics Technology Letters.

[3]  T. Tsuchizawa,et al.  Low loss mode size converter from 0.3 /spl mu/m square Si wire waveguides to singlemode fibres , 2002 .

[4]  Tony C. Kowalczyk,et al.  Polymer variable optical attenuator arrays: pathway from material platform to qualified telecom product , 2004, SPIE Optics + Photonics.

[5]  R. Soref,et al.  Electrooptical effects in silicon , 1987 .

[6]  Toshifumi Watanabe,et al.  Si wire waveguide devices , 2007, SPIE Optics East.

[7]  Yasuhiko Ishikawa,et al.  Effect of Post-Growth Annealing on Morphology of Ge Mesa Selectively Grown on Si , 2008, IEICE Trans. Electron..

[8]  Hiroshi Fukuda,et al.  Low-loss Si wire waveguides and their application to thermooptic switches , 2006 .

[9]  Wim Bogaerts,et al.  A polarization-diversity wavelength duplexer circuit in silicon-on-insulator photonic wires. , 2007, Optics express.

[10]  Nahum Izhaky,et al.  High-speed optical modulation based on carrier depletion in a silicon waveguide. , 2007, Optics express.

[11]  R.F. Drayton,et al.  Congratulations to the 2005 MTT-S Undergraduate/Pregraduate Scholarship Awardees! , 2006, IEEE Microwave Magazine.

[12]  D. Van Thourhout,et al.  Compact Wavelength-Selective Functions in Silicon-on-Insulator Photonic Wires , 2006, IEEE Journal of Selected Topics in Quantum Electronics.

[13]  T. Tsuchizawa,et al.  Silicon photonic circuit with polarization diversity. , 2008, Optics express.

[14]  L. Sekaric,et al.  Ultra-compact, low RF power, 10 Gb/s silicon Mach-Zehnder modulator. , 2007, Optics express.

[15]  Ansheng Liu,et al.  Issues Associated With Polarization Independence in Silicon Photonics , 2006, IEEE Journal of Selected Topics in Quantum Electronics.

[16]  T. Shoji,et al.  Microphotonics devices based on silicon microfabrication technology , 2005, IEEE Journal of Selected Topics in Quantum Electronics.

[17]  Horng-Dean Chen.  Compact CPW-fed dual-frequency monopole antenna , 2002 .