Semiconductor system having a ring laser fabricated by expitaxial 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 method of making a ring laser-system, comprising:
forming a substantially planar and horizontal buffer layer having a first top surface;
forming a substantially planar and horizontal intermediate layer 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;
forming an optical core by ELOG in the ELOG opening over the first top surface and over the second top surface of the intermediate layer such that at least portions of the optical core extend vertically above the buffer layer and the intermediate layer, the vertical core comprising non-horizontal sidewalls disposed about an outer periphery thereof located above the second top surface;
forming along the outer periphery and in contact with the sidewalls of the optical core a plurality of non-horizontal multi-quantum well layers and a plurality of non-horizontal barrier layers disposed therebetween; and
forming an outer structure surrounding the plurality of non-horizontal multi-quantum wells and the plurality of non-horizontal barrier layers;
wherein the 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 cavity, and at least portions of the outer structure are configured to totally internally reflect the photons.
2. The method of claim 1 wherein forming the multi-quantum wells further comprises forming barrier layers and quantum well layers in an alternating vertical stripe pattern surrounding the optical core.
3. The method of claim 1 , further comprising forming a transverse N-I-P structure across the multi-quantum wells, the N-I-P structure being configured to generate the photons during a lasing function.
4. The method of claim 1 , further comprising establishing a spontaneous emission wavelength of the laser ring system in accordance with a horizontal thickness, composition, and spacing of the quantum well layers, wherein the spontaneous emission wavelength matches at least one resonant frequency of the optical cavity.
5. The method of claim 1 , further comprising forming at least one of a p-contact and an n-contact on the ring laser system.
6. The method of claim 1 , further comprising forming the n-contact over the optical core and forming the p-contact over the outer structure.
7. The method of claim 1 , further comprising etching grooves in the ring laser structure to form a second order grating.
8. The method of claim 7 , further comprising etching the grooves in the outer structure.
9. The method of claim 1 , further comprising forming a discontinuity adjacent a portion of the outer structure.
10. The method of claim 9 , further comprising forming the discontinuity and the outer structure such that a first index of refraction of the discontinuity is less than a second index of refraction of the outer structure.