High power single mode fiber laser
AssigneeIpg Photonics Corporation
InventorsAnton Ferin, Valentin Fomin, Andrey Abramov
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Abstract
A single mode (SM) high power laser system is configured with a laser source outputting a single mode or low mode kW-power light and a passive delivery fiber spliced to an output fiber of the fiber laser source and having a double bottleneck-shaped core. The latter is configured to increase a threshold for nonlinear effects in general and in particular for stimulated Raman scattering (SRS) so that the delivery passive fiber has a fiber length at least twice the length of a delivery passive fiber with a standard uniformly dimensioned core, which may be used with the same laser source, while outputting the kW-power light with an M2 factor less than 2.
Claims10
A high power laser system, comprising:
- a laser source outputting a single mode (SM) or low order mode kW-power light and having at least one fiber gain block which has an active fiber and an output SM passive fiber;
- a passive delivery fiber spliced to the output SM passive fiber of the laser source and configured to have a double bottleneck-shaped core that is monolithic and includes:
- an input end section receiving the kW power light from the laser source and an output end section, the input and output end sections each having a uniform diameter which is dimensioned to support the single mode;
- a uniformly-dimensioned central section located between and having a diameter greater than that of each of the input and output end sections of the core, the central section of the core being dimensioned to support multiple modes;
- and
- input and output tapered sections extending between respective opposite ends of the central section and the respective input and output end sections,
- the passive delivery fiber increasing a threshold of nonlinear effects so that the passive delivery fiber has a fiber length at least twice the length in comparison to a length of a passive delivery fiber with a uniformly dimensioned core, while outputting the kW-power light with a beam quality factor M2 less than 2.
Dependencies are inferred from the claim text.