Femtosecond semiconductor-based optoelectronic devices for optical-communication systems

Compact semiconductor-based ultrafast optoelectronic devices are crucial for networks with a throughput in the 1–10 Tb/s range. A variety of ultrafast phenomena in semiconductors are attractive for developing such new optoelectronic devices. This paper discusses the requirements of ultrafast optical-communication systems and necessary optoelectronic devices. Recent progress of ultrafast semiconductor-based optoelectronic devices are described with a focus on all-optical switching devices, including novel devices using electron spin polarization relaxation and intersubband transition both in multiple quantum well structures.