Numerical Analysis of Carrier-Depletion Strained SiGe Optical Modulators With Vertical p-n Junction

作者：Kim Younghyun^*; Takenaka Mitsuru; Takagi Shinichi

来源：IEEE Journal of Quantum Electronics, 2015, 51(4): 5200107.

DOI：10.1109/JQE.2015.2405931

• Strained SiGe
• optical modulator
• vertical p-n junction
• Si photonics

The modulation characteristics of carrier-depletion strained SiGe optical modulators with a vertical p-n junction are numerically analyzed by technology computer-aided design simulation and finite-difference optical mode analysis. In addition to the strong optical confinement in the vertical direction for the fundamental transverse electric field mode, the vertical p-n junction effectively depletes the strained SiGe layer in which the plasma dispersion effect is enhanced owing to the mass modulation of holes by strain. We predict that a Si0.7Ge0.3 optical modulator exhibits V pi L at 1.55 mu m of as small as 0.31 V-cm at a bias voltage of -2 V, which is similar to 1.8 times smaller than that of a Si optical modulator. The product of V pi L and the phase-shifter loss (alpha V pi L) is also expected to be as low as 18.3 V-dB at -2 V, enabling optical modulation with a 5-dB extinction ratio in a symmetric Mach-Zehnder modulator.

• 出版日期2015-4