Integrated laser and electro-absorption modulator with improved extinction

A modulated light emitter comprising:

• a first contact layer of a first semiconductor type;
• a first cladding layer on said contact layer of said first semiconductor type;
• an active layer comprising a quantum well (QW) layer sandwiched between first and second barrier layers;
• a second cladding layer of the opposite semiconductor type;
• and
• a second contact layer of said opposite semiconductor type;
• wherein said active layer comprises a laser region and a modulator region, said laser region emitting light when a potential is applied across said active layer in said laser region and said modulator region having a first state in which said modulator region absorbs said generated light and a second state in which said modulator region transmits said generated light, said modulator region assuming either said first or second state depending on the potential across said modulator region, wherein said QW layer in said modulator region is under a tensile strain, and
• wherein said barrier layers in said modulator region are under less tensile strain than said QW layer, and,
• wherein said barrier layers in said modulator region are under a compressive strain.