Fundamental characteristics and high-speed applications of carrier-depletion silicon Mach-Zehnder modulators

Carrier-depletion Si Mach-Zehnder modulators incorporating lateral PN-junction phase shifters are reviewed in the lights of fundamental characteristics and applications to high-speed optical fiber transmission. Experimental reverse-bias characteristics are supported by numerical analysis with good agreement, implying that the Si modulators are fabricated precisely as designed. Numerical high-speed response proves that the phase shifter operates beyond 100-Gbaud symbol rate. Traveling-wave electrodes are characterized in S-parameter measurements to reveal LRC resonance as a limiting factor in high-speed modulation. High-speed optical-fiber transmission in on-off and phase-shift keying formats is demonstrated using the Si Mach-Zehnder modulators assembled in ceramic-based metal packages.