The development of future electronic-photonic integrated circuits (EPIC) based on silicon technology critically depends on the availability of CMOS-compatible high-speed modulators that enable the interaction of electronic and optical signals. This thesis investigates electrically driven Mach-Zehnder modulators based on high-index contrast silicon waveguide technology and electronic carrier injection. Modulators based on four different structures are investigated: the forward-biased PiN diode with and without lifetime reduction, the reverse-biased PIN/PN diode and a metal-oxide-semiconductor (MOS) structure. These devices are compared with each other in terms of achievable performance. A modulator based on the forward-biased PIN diode with lifetime reduction is designed to reach 34GHz bandwidth and a low figure of merit V -. L = 0.6V - cm using a carrier lifetime reduction and a graded doping profile. A bandwidth of 1-2GHz has been demonstrated so far which is considerably smaller than the design bandwidth due to high series resistance. Modulators based on the forward-biased PIN structure without lifetime reduction have a low figure of merit, very low voltage and extremely low power consumption in the low frequency regime.
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