Performance comparison between vertical-cavity surface-emitting laser and quantum-well modulator for short-distance optical links

We quantify and compare two competing transmitter technologies: vertical-cavity surface-emitting laser (VCSEL) and quantum-well modulator (QWM) for the interchip communication using high-speed optical links. VCSEL-based links are power favorable compared to QWM-based links at higher bandwidths (20 Gb/s) and larger distances. However, the QWM is better for lower detector capacitances. We also extend the comparison to high-speed electrical links and quantify the critical length beyond which optical links are power favorable compared to electrical links for both VCSEL and QWM transmitters.