Current and future trend of energy/bit for high speed uncool optical links (50 Gb/s and 75°C)

VCSEL bandwidth is limited by slow e-h recombination lifetime nanosecond to ~ 30 GHz (60Gb/s). The transistor laser (TL) has picosecond radiative recombination lifetime; thus, it will have modulation bandwidth higher than VCSELs toward 150 GHz to achieve 300 Gb/s error free transmission and low power operation of energy/bit toward 10 fJ/bit.