Multiple phonon resonance quantum cascade lasers
US7609738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2007 |
| Grant date | Oct 27, 2009 |
| Priority date | — |
| Expiry date | Dec 27, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/12
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Quantum-cascade lasers are provided with an active section in which relaxation of carriers from a lower laser level is provided by three or more phonon-assisted transitions to levels within the active section whose energies are below the energy of the lower laser level. The gain region of the laser consists of alternating active and injector sections, with an injection barrier inserted between each injector section and the adjacent active section, and an exit barrier inserted between each active section and the adjacent injector section. The active section comprises a sufficient number of quantum wells separated by quantum barriers to produce the desired energy-level structure consisting of an upper laser level, a lower laser level, and at least three levels that have lower energies than the lower laser level, with the separation of adjacent energy levels below and including the lower laser level that are at least equal to the energy of the quantum well material's longitudinal optical phonon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.