Energy efficiency of 100 fJ/bit for bit rates beyond 50 Gb/s for 940 nm single mode VCSELs

We demonstrate major advancements in the energy efficiency of single mode, oxide-confined, vertical-cavity surface-emitting lasers at 940 nm wavelength, being promising for optical interconnects. We were able to show error-free operation (Bit Error Rate of 10exp -12) at 50 Gb/s and at 60 Gb/s, for Non-Return-to-Zero modulation across 100 m of multimode optical fiber with an energy efficiency of 98/168 fJ/bit, respectively. These are presently the most energy-efficient directly modulated light sources available for data transmission.