Monolithic integration of spot-size converters with 1.3-Μmlasers and 1.55-Μm polarization insensitive semiconductor opticalamplifiers

摘要

To reduce packaging costs, it is necessary to use passivenalignment between the laser diodes and optical fiber. Such an alignmentnrequires low-coupling loss and large positional alignment tolerances.nThis is achievable with integrated spot-size converters, which permit tonmatch the near field of a laser to that of a flat-end single-mode fibern(SMF). In this paper, we first review briefly the differentntechnological approaches to realize spot-size converters. Then, we focusnon the double-core structure developed both for 1.3-Μm Fabry-Perotnlasers and 1.55-Μm semiconductor optical amplifiers (SOAs). Thenspot-size expansion is simulated using a two-dimensional (2-D) beamnpropagation method analysis. Short spot-size converters (100 Μm)nintegrated with 1.3-Μm lasers and 1.55-Μm SOAs exhibit beamndivergences as low as 12°×12° and 12°×15°,nrespectively. The performances of devices with integrated spot-sizenconverters are reported and discussed. A 2-in wafer process is usednthanks to the versatility of the double-core structure and itsncompatibility with buried ridge stripe technology