Electroabsorption modulator having a barrier inside a quantum well

An electroabsorption modulator apparatus comprising:

• at least one first quantum well in a conduction band;
• a corresponding second quantum well in a valence band;
• a first barrier formed within said first quantum well;
• and
• a second barrier formed within said second quantum well;
• wherein said first and second barriers are formed from InGaAlAs.

An electroabsorption modulator apparatus comprising:

• at least one first quantum well in a conduction band;
• a corresponding second quantum well in a valence band;
• a first barrier formed within said first quantum well;
• a second barrier formed within said second quantum well;
• wherein said first and second barriers are formed from InGaAsP;
• a third barrier defining one side of said first well in said conduction band;
• a fourth barrier defining one side of said second well in said valence band;
• wherein said third and fourth barriers are formed from InP or InGaAsP, and said first and second wells are formed from InGaAs or InGaAsP.

An electroabsorption modulator apparatus comprising:

• first and second electrically conductive electrodes;
• first and second cladding layers provided between said first and second electrodes;
• and
• a quantum well layer provided between said first and second cladding layers, said well layer including an InP first region, an InGaAs second region adjacent said first region, and an InGaAsP third region adjacent said second region;
• a substrate provided between said first electrode and said first cladding layer;
• a contact layer provided between said second electrode and said second cladding layer;
• and
• a buffer layer provided between said contact layer and said second cladding layer.

A method for delaying a red shift of a quantum-confined Stark effect to a higher electric field, and increasing transition energy and an oscillator strength response after the onset of the red shift, in an electroabsorption modulator, said method comprising the steps of:

• creating at least one first quantum well in a conduction band;
• creating at least one corresponding second quantum well in a valence band;
• forming a first barrier in a portion of said first quantum well;
• and
• forming a second barrier in a portion of said second quantum well;
• wherein said first and said second barriers are formed from InGaAlAs.

A method for delaying a red shift of a quantum-confined Stark effect to a higher electric field, and increasing a transition energy and an oscillator strength response after the onset of the red shift, in an electroabsorption modulator, said method comprising the steps of:

• creating at least one first quantum well in a conduction band;
• creating at least one corresponding second quantum well in a valence band;
• forming a first barrier in a portion of said first quantum well;
• and
• forming a second barrier in a portion of said second quantum well;
• wherein said first and said second barriers are formed from InGaAsP.