Coupled quantum well optical intensity modulator for INP based optoelectronic integrated circuits and methods therefor

An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising:

• a core layer for transmitting an optical signal;
• an active cladding contiguous to the core layer, said active cladding including a plurality of optically coupled quantum well structures, each optically coupled quantum well structure including a pair of optically coupled quantum wells physically separated by a barrier, each optically coupled quantum well structure being contiguous to another of the plurality of optically coupled quantum well structures and physically separated from the other of the optically coupled quantum well structures by a semi-insulating optically decoupling barrier for optically decoupling the optically coupled quantum well structures from each other;
• a first additional cladding;
• a second additional cladding, said core layer and said active cladding being interposed between the first and second additional claddings;
• and
• a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.

An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising:

• an n+ doped cap layer formed on the substrate;
• an n doped cladding formed on the n+ doped cap layer;
• an n doped core layer formed on the n doped cladding for transmitting an optical signal;
• an active cladding including at least one pair of optically coupled quantum wells physically separated by a barrier, said active cladding being formed on the core layer;
• a p doped cladding formed on the active cladding;
• a p+ doped cap layer formed on the p doped cladding;
• and
• a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.