Methods, systems, and apparatus for coherent beam combining
US9134538B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 2013 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | Mar 1, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Coherent beam combining of laser gain elements achieves high output power in a diffraction limited beam. An active beam combining system coherently combines optical beams emitted by semiconductor laser gain elements in an external resonant cavity configuration. A beam combiner in the resonant cavity combines the outputs of the laser gain elements into a single coherent output beam whose power is monitored by a photodetector. A processor uses the photodetector's output to adjust the phases of the respective optical beams emitted by the laser gain elements so as to increase or maximize the coherent output beam's power. The processor may vary the optical beams' phases according to a stochastic parallel gradient descent (SPGD) algorithm for active phase control. Experimental results show a beam combining efficiency of 81% with an upper limit of 90% or higher and without the scaling limits imposed on passive-phasing systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.