Gigabit data rates are becoming relevant for several applications areas, including computer interconnections, trunk telecommunications, and phased-array radar control. LED\´s, lasers, p-i-n FET\´s, photoconductors, and avalanche photodiodes are candidate components. Silicon NMOS, bipolar, GaAs FET, and heterojunction bipolar logic IC technologies are all appropriate and no obstacles are apparent to prevent direct modulation to

Gbit/s. Wavelength multiplexing will impact strongly in several applications enabling complex new system architectures. Increasing speed and complexity will drive technology to higher optoelectronic integration levels.