Optical sources having a strongly scattering gain medium providing laser-like action
US5448582A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1994 |
| Grant date | Sep 5, 1995 |
| Priority date | — |
| Expiry date | Mar 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A gain medium is comprised of a multi-phase system wherein: a first phase is an electromagnetic radiation emission phase; a second phase is an electromagnetic radiation scattering phase; and a third phase is a transparent matrix phase. By example, the emission phase may consist of dye molecules, the scattering phase may consist of high contrast particles, and the matrix phase may consist of a solvent such as methanol. In some embodiments of this invention the emission and scattering phases may be the same phase, as when semiconductor particles are employed. A smallest dimension of a body comprised of the gain medium may be less than a scattering length associated with the scattering phase. It is shown that nearly thresholdless laser behavior is observed in strongly scattering optically pumped dye-methanol solutions containing colloidal TiO.sub.2 or Al.sub.2 O.sub.3 ruby nanoparticles. The emission from the high gain colloid exhibits a slope change in the linear input-output characteristics above a critical pump pulse energy. The change in slope is accompanied by a spectral line narrowing with a bichromatic spectrum appearing at high pump energies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.