Performance comparison of InGaAsP lasers emitting at 1.3 and 1.55 µm for lightwave system applications

Experimental results relative to the performances of real index-guided InGaAsP lasers emitting near 1.3 and 1.55 μm are described and compared. The laser structures discussed are the etched mesa buried heterostructure, channeled substrate buried heterostructure, and the double channel planar buried heterostructure. The effect of Auger recombination and intervalence band absorption on the threshold current and external differential quantum efficiency is discussed. The effect of the larger Auger coefficient at 1.55 μm is compensated by a lower carrier density at threshold at 1.55 μm so that the total nonradiative current loss for lasers emitting at 1.55 μm is not significantly larger than that for lasers emitting at 1.3 μm. A small linear shunt leakage current (∼10 mA) can increase the T
0
to ∼100K. We report threshold currents as low as 11 and 15 mA (at 30°C) and continuous-wave operating temperatures as high as 130 and 110°C for lasers emitting at 1.3 and 1.55 μm, respectively.