Integrated optical modeshape adapters in InGaAsP/InP for efficient fiber-to-waveguide coupling

A concept for integrated optical modeshape adapters (IOMA's) for efficient fiber-to-waveguide coupling is realized in InGaAsP/InP. The integrated optical modeshape adapters (IOMA's) combine vertically tapered waveguide cores with simultaneously up-tapered upper claddings. Their OEIC-compatible fabrication process is based on diffusion-limited etching for the waveguide core tapers and selective area regrowth with LP-MOVPE for the up-tapered upper claddings, both using the same dielectric mask. First realized devices, when coupled to lensed single-mode fibers (SMF's), show optical losses as low as 1 dB per facet at 1.53- mu m wavelength.<
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