Single-frequency fiber amplifier with distal cladding stripper
US11108209B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 2020 |
| Grant date | Aug 31, 2021 |
| Priority date | — |
| Expiry date | May 1, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/03
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Stimulated Brillouin scattering (SBS) limits the maximum power in fiber lasers with narrow linewidths. SBS occurs when the power exceeds a threshold proportional to the beam area divided by the effective fiber length. The fiber lasers disclosed here operate with higher SBS power thresholds (and hence higher maximum powers at kilohertz-class linewidths) than other fiber lasers thanks to several techniques. These techniques include using high-absorption gain fibers, operating the laser with low pump absorption (e.g., ≤80%), reducing the length of un-pumped gain fiber at the fiber output, foregoing a delivery fiber at the output, foregoing a cladding light stripper at the output, using free-space dichroic mirrors to separate signal light from unabsorbed pump light, and using cascaded gain fibers with non-overlapping Stokes shifts. The upstream gain fiber has high absorption and a larger diameter for high gain, and subsequent gain fiber has a smaller diameter to improve beam quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.