Dopant diffusion blocking for optoelectronic devices using InAlAs and/or InGaAlAs

An optoelectronic device comprising:

• a substrate of a first type conductivity;
• a mesa structure provided on said substrate, said mesa structure having a least two sides and including an active region, said active region further being bounded on at least one side by an undoped dopant blocking layer, said undoped dopant blocking layer comprising a material selected from the group consisting of InAlAs and InGaAlAs;
• a first current blocking layer at two sides of said mesa structure;
• a second current blocking layer of a first type conductivity formed over said first current blocking layer;
• and
• a cladding layer of a second conductivity type formed over said mesa structure and said second blocking layer, said dopant blocking layer being situated between each of said two sides of said mesa structure and said first current blocking layer.

A semiconductor optical device comprising:

• a substrate of a first type conductivity;
• a mesa structure provided on said substrate, said mesa structure having two sides and including an active region;
• and
• a first undoped dopant blocking layer at two sides of said mesa structure, said undoped dopant blocking layer comprising a material selected from the group consisting of InAlAs and InGaAlAs.

A semiconductor optical device comprising:

• a substrate of a first type conductivity;
• a mesa structure provided on said substrate, said mesa structure having two sides and including an active region, said mesa structure further including a first undoped dopant blocking layer in contact with said active region, said first undoped dopant blocking layer comprising a material selected from the group consisting of InAlAs and InGaAlAs;
• and
• a second undoped dopant blocking layer at two sides of said mesa structure.