High-performance densely packed vertical-cavity photonic integrated emitter arrays for direct-coupled WDM applications

High-performance multiple-wavelength photonic integrated InGaAs-GaAs MQW DBR VCSEL laser emitter arrays with a manufacturable planar scheme are demonstrated for low-cost multimode wavelength-division-multiplexing (WDM) local-area networks. Each array consists of eight pie-shaped bottom-emitting vertical-cavity lasers (VCL's) enclosed within a 60-μm-diameter circle for direct-coupling into a single multimode fiber. The arrays exhibit a wide 32.9-nm lasing wavelength span and relatively high 7.3-mW single-channel output. In particular, we have achieved a differential efficiency as high as 50.2% and a maximum wall-plug efficiency of 11.8%. These devices operate with multilateral modes and have a wide 3-dB spectral bandwidth of 1.7 nm in average, which makes them especially suitable for multimode fiber systems.