Article comprising a dual-wavelength quantum cascade photon source
US6144681A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1998 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Mar 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/1096
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The quantum cascade (QC) photon source according to this invention can emit simultaneously at two distinct wavelengths, typically both in the mid-infrared. This is accomplished through provision of a semiconductor layer structure in which, at the proper bias voltage, electrons are injected into an energy level E.sub.3 and then forced to cascade through an intermediate level E.sub.2 before reaching the ground state E.sub.1 of the active region. In the process, photons of energy E.sub.3 -E.sub.2 (wavelength .lambda..sub.1) and E.sub.2 -E.sub.1 (wavelength .lambda..sub.2) are emitted. Dual wavelength photon sources according to this invention can be used in a variety of ways, e.g., to determine the absorption of a gaseous sample at wavelengths .lambda..sub.1 and .lambda..sub.2, exemplarily to determine the concentration of a particular chemical compound in the sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.