A PAM-4 100 Gbps single-drive strained SiGe optical lumped Mach-Zehnder modulator for O-band application

Abstract

We propose the carrier-depletion type strained SiGe optical lumped Mach-Zehnder modulators (MZMs) with L-shape PN junction (LSPN) with a highly CMOS-compatible fabrication method. The device performance is numerically investigated and optimized by technology computer-aided design (TCAD) simulation. The optimized SiGe LSPN MZ modulator exhibits a high modulation efficiency of 0.52 Vcm for VπL with reverse bias voltages of 0V to -2V at 1310 nm wavelength, which is 3.5 times smaller than the conventional PN junction device thanks to strained SiGe. Furthermore, we carried out the large-signal simulation with 1-mW input power. As a result, we found that the SiGe LSPN MZ modulator can achieve 0.54 mW (-2.7 dBm) and 0.17 mW (-7.7 dBm) eye-openings for 50-Gbps NRZ-OOK and 100-Gbps PAM-4, respectively, taking advantage of single-drive configuration and optimizing input characteristics impedance. We expect this SiGe lumped MZ modulator can be one of the promising solutions for replacing a very long Si MZ modulator with traveling-wave electrodes. IEEE