Integration of direct-bandgap optically active devices on indirect-bandgap-based substrates

An apparatus comprising:

• a substrate comprising single-crystal silicon;
• and
• a laser structure comprising an active region having:
• a first plurality of light-emitting regions, each light-emitting region of the first plurality thereof comprising a first material that is a first compound semiconductor having a first bandgap (Eg1);
• and
• a first confinement layer that substantially completely surrounds each of the first plurality of light-emitting regions, wherein the first confinement layer comprises a second material that is a second compound semiconductor having a second bandgap (Eg2) that is greater than the first bandgap, and wherein the second material is characterized by a defect-related trap level (Edefect) that substantially suppresses recombination-enhanced defect-reaction-driven degradation of the laser structure;
• wherein at least one of the first plurality of light-emitting regions is a structure selected from the group consisting of quantum dots, quantum wires, and quantum dashes;
• wherein the first plurality of light-emitting regions and the first confinement layer collectively provide spatial and electrical charge-carrier confinement;
• and
• wherein the laser structure and the substrate are monolithically integrated and in direct contact.

A method for forming a photonic integrated circuit (PIC) comprising:

• forming an active optical device on a substrate that comprises an indirect-bandgap semiconductor, the active optical device comprising an active region having:
• at least one light-emitting region that comprises a first material that is a direct-bandgap semiconductor having a first bandgap (Eg1);
• and
• a confinement layer that substantially completely surrounds the at least one light-emitting region, wherein the confinement layer comprises a second material having a second bandgap (Eg2) that is greater than the first bandgap;
• wherein the at least one light-emitting region and the confinement layer are collectively operative for providing spatial and electrical charge-carrier confinement in at least two dimensions;
• and
• providing a surface waveguide that is disposed on the substrate;
• wherein the active region and the surface region are optically coupled;
• and wherein at least a portion of the active optical device is formed via epitaxial growth on the substrate.