Spatially coherent surface-emitting, grating coupled quantum cascade laser with unstable resonance cavity
US6560259B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 2001 |
| Grant date | May 6, 2003 |
| Priority date | — |
| Expiry date | Oct 10, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/3215
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A surface emitting, unipolar, quantum cascade semiconductor laser is constructed of a multilayer semiconductor structure on a substrate. The laser has doped semiconductor material only of one conductivity type. The laser includes a core region having a larger effective refractive index than cladding regions. The core region includes a plurality of repeat units, each repeat unit having a nominally identical active region and a carrier injection and relaxation region. The repeat units are for quantum cascade generation of a lasing resonance mode within a lasing resonance cavity of the multilayer semiconductor structure. A diffraction grating is fabricated within the multilayer semiconductor structure. The grating resonantly couples diverging counter-propagating traveling wave beams of the laser resonance mode while also diffracting light into an upward direction perpendicular to a grating plane and toward the substrate surface, and also into a downward direction. A mirror reflects the downwardly coupled light toward the upward direction again. The optical distance between reflecting mirror and the grating is selected to combine the reflected light with the upwardly coupled light in-p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.