1.55-μm bipolar cascade segmented ridge lasers

Abstract

Scalable bipolar cascade lasers are achieved by electrically segmenting an InP ridge laser, and then series-connecting the segments. Lasers with up to 12 stages are demonstrated with record 390% continuous wave differential efficiency, and very low threshold currents. Three-stage lasers with 50-/spl Omega/ input impedance and over 100% differential efficiency are modulated with 2.5-GB/s digital data, and have 5-GHz analog modulation bandwidth. Noise and distortion properties are at least as good as single-stage control lasers.