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Journal of Lightwave Technology

Journal of Lightwave Technology


  • Vol. 29, Iss. 1 — Jan. 1, 2011
  • pp: 48–52

Conductor Loss of Capacitively Loaded Slow Wave Electrodes for High-Speed Photonic Devices

JaeHyuk Shin , Steven R. Sakamoto, and Nadir Dagli

Journal of Lightwave Technology, Vol. 29, Issue 1, pp. 48-52 (2011)

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In this paper, analytical expressions are presented for the microwave attenuation of slow wave electrodes obtained by periodically loading a regular coplanar line with capacitive elements. Such electrodes are commonly used in III-V compound semiconductor electro-optic modulators and other traveling wave devices. These results are obtained by modifying the existing analytical loss expressions for regular coplanar lines based on physical arguments. The predictions of these expressions are compared with experimental results up to 35 GHz and agreement is found to be very good. Validity of this analysis is also discussed. It is found that the approach works very well for lines of practical interest. Hence, the proposed approach enables complete design of capacitively loaded slow wave electrodes by predicting the microwave loss with closed-form equations in addition to velocity and characteristic impedance.

© 2010 IEEE

JaeHyuk Shin , Steven R. Sakamoto, and Nadir Dagli , "Conductor Loss of Capacitively Loaded Slow Wave Electrodes for High-Speed Photonic Devices," J. Lightwave Technol. 29, 48-52 (2011)

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  1. R. G. Walker, "High speed III-V electrooptic waveguide modulators," IEEE J. Quantum Electron. 27, 654-667 (1991).
  2. R. Spickermann, S. R. Sakamoto, M. G. Peters, N. Dagli, "GaAs/AlGaAs traveling wave electrooptic modulator with electrical bandwidth greater than 40 GHz ," Electron. Lett. 32, 1095-1096 (1996).
  3. N. Dagli, "Wide bandwidth lasers and modulators for RF photonics," IEEE Trans. Microw. Theory Technol. 47, 1151-1171 (1999).
  4. L. Zhang, J. Sinsky, D. Van Thourhout, N. Sauer, L. Stulz, A. Adamiecki, S. Chandrasekhar, "Low voltage high speed travelling wave InGaAsP/InP phase modulator," IEEE Photon. Technol. Lett. 16, 1831-1833 (2004).
  5. K. Tsuzuki, T. Ishibashi, T. Ito, S. Oku, Y. Shibata, T. Ito, R. Iga, Y. Kondo, Y. Tohmori, "A 40-Gb/s InGaAlAs-InAlAs MQW n-i-n Mach–Zehnder modulator with a drive voltage of 2.3 V ," IEEE Photon. Technol. Lett. 17, 46-48 (2005).
  6. S. Akiyama, H. Itoh, T. Takeuchi, A. Kuramata, T. Yamamoto, "Wide-wavelength-band (30 nm) 10-Gb/s operation of InP-based Mach–Zehnder modulator with constant driving voltage of 2 vpp," IEEE Photon. Technol. Lett. 17, 1408-1410 (2005).
  7. J. Shin, S. Wu, N. Dagli, "35 GHz bandwidth, 5 V-cm drive voltage, bulk GaAs substrate removed electro optic modulators ," IEEE Photon. Technol. Lett. 19, 1362-1364 (2007).
  8. H. Chen, Y. Kuo, J. E. Bowers, "High speed hybrid silicon evanescent Mach–Zehnder modulator and switch," Opt. Exp. 16, 20571-20576 (2008).
  9. H. Chen, Y. Kuo, J. E. Bowers, "25 Gb/s hybrid silicon switch using a capacitively loaded traveling wave electrode," Opt. Exp. 18, 1070-1075 (2010).
  10. L. Y. Lin, M. C. Wu, T. Itoh, T. A. Vay, R. E. Muller, D. L. Sivco, A. Y. Cho, "Velocity-matched distributed photodetectors with high-saturation power and large bandwidth ," IEEE Photon. Technol. Lett. 8, 1376-1378 (1996).
  11. M. S. Islam, S. Murthy, T. Itoh, M. C. Wu, D. Novak, R. B. W. House, D. L. Sivco, A. Y. Cho, "Velocity-Matched distributed photodetectors and balanced photodetectors with p-i-n photodiodes ," IEEE Trans. Microw. Theory Techn. 49, 1914-1920 (2001).
  12. R. Spickermann, S. R. Sakamoto, N. Dagli, "In traveling wave modulators which velocity to match?," IEEE Lasers and Electro-Optics Society 1996 Annual Meeting BostonMA (1996) Paper WM3.
  13. J. Shin, C. Ozturk, S. R. Sakamoto, Y. J. Chiu, N. Dagli, "Novel T-rail electrodes for substrate removed low-voltage high-speed GaAs/AlGaAs electro-optic modulators," IEEE Trans. Microw. Theory Techn. 53, 636-643 (2005).
  14. S. Sakamoto, R. Spickermann, N. Dagli, "Novel narrow gap coplanar slow wave electrode for traveling wave electrooptic modulators ," Electron. Lett. 31, 1183-1185 (1995).
  15. G. E. Ponchak, M. Matloubian, L. P. B. Katehi, "A measurement-based design equation for the attenuation of MMIC-compatible coplanar waveguides ," IEEE Trans. Microw. Theory Techn. 47, 241-243 (1999 ).

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