Semiconductor system having a ring laser fabricated by epitaxial layer overgrowth
View Patent ↗The present invention provides a ring laser system comprising forming an optical core by an epitaxial layer overgrowth over an intermediate layer, forming multi-quantum wells adjacent to the optical core and forming an outer structure further comprising a total internal reflector, wherein forming photons within the multi-quantum wells further comprises circulating the photons within the ring laser structure comprising the outer structure, the multi-quantum wells, and the optical core.
1. A ring laser system, comprising:
a substantially planar and horizontal buffer layer having a first top surface;
a substantially planar and horizontal intermediate layer disposed atop the first top surface, the intermediate layer having a second top surface and a second bottom surface, the second bottom surface adjoining the first top surface, at least one epitaxial layer overgrowth (ELOG) opening being disposed through portions of the intermediate layer and extending between the second top surface and the second bottom surface
an optical core formed by ELOG disposed in the ELOG opening and disposed over the first top surface and over the second top surface of the such that at least portions of the optical core extend vertically above the buffer layer and the intermediate layer, the optical core comprising non-horizontal sidewalls disposed about an outer periphery thereof located above the second top surface;
a plurality of non-horizontal multi-quantum wells disposed along the outer periphery and in contact with the sidewalls of the optical core
a plurality of non-horizontal barrier lavers disposed between the non-horizontal multi-quantum wells; and
an outer structure surrounding the plurality of non-horizontal multi-quantum wells and the plurality of non-horizontal barrier layers;
wherein the multi-quantum wells are configured to form photons, the ring laser system is configured to circulate the photons therein among one or more of the outer structure, the multi-quantum wells, and the optical core, and at least portions of the outer structure are configured to totally internally reflect the photons.
2. The system of claim 1 , wherein the multi-quantum wells further comprise barrier layers and quantum well layers configured in an alternating vertical stripe pattern.
3. The system of claim 1 , further comprising a transverse N-I-P structure disposed across the multi-quantum wells, the N-I-P structure being configured to generate photons during a lasing function.
4. The system of claim 1 , wherein horizontal thicknesses and spacings of the quantum well layers within the multi-quantum wells are configured to establish a spontaneous emission wavelength matching at least one resonant frequency of the optical core.
5. The system of claim 1 , wherein the outer structure further comprises a discontinuity comprising a dielectric layer, a diffraction grating, or a notch disposed by a facet, the discontinuity being configured to provide a less reflective path for photon emission.
6. The system of claim 1 , wherein the outer structure further comprises a second order grating comprising etched grooves.
7. The system of claim 1 , wherein the outer structure forms a total internal reflector.
8. The system of claim 2 , wherein the alternating vertical stripe pattern comprises n quantum well layers and n+1 barrier layers.
9. The system of claim 2 , wherein the thicknesses and spacings of the quantum well layers and the barrier layers, and the dimensions of the optical cavity, are configured to determine the lasing wavelength.
10. The system of claim 1 , further comprising a p-contact and an n-contact for electrical connection.