1.55-$\mu$m VCSEL Arrays for High-Bandwidth WDM-PONs

Monolithically integrated long-wavelength vertical-cavity surface-emitting laser arrays of 4, 8, and 12 high-speed devices are presented. These devices have a lithographically defined pitch of 250 μm and feature a per-channel bandwidth of 10 Gb/s over 20 km of standard single-mode fiber. The output performance is very homogenous for the whole array. Emission wavelength is addressable by current-tuning without any bit-error-rate penalty. This allows highly scalable bandwidth for metro-range networks. Through the migration from coarse wavelength-division-multiplexed (WDM) to dense WDM operation, a bandwidth upgrade from 2.5 to 80 Gb/s is feasible without any further investment into the transmitter infrastructure.