Pulsed laser system with optimally configured saturable absorber
AssigneeIpg Photonics Corporation
InventorsSergey Maryashin, Andrey Unt
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Abstract
A high power pulsed laser system is configured with at least two gain blocks and with at least one saturable absorber (SA) coupled to the output and input of the respective gain blocks. The SA is configured so that Qsat_sa<Qsat_gb, wherein Qsat_sa is a saturation energy of the SA, and Qsat_gb is a saturation energy of the gain blocks. The SA is further configured with a recovery time τ<1/f providing for the substantially closed state of the SA, wherein the f is a pulse repetition rate, and with the recovery time τ smaller than a round trip time Tround_trip=2*(L1+L2)*n/c, where L1, L2—lengths of the respective gains gain blocks, n—a refractive index of active media, c—a speed of light in vacuum.
Claims10
A multi-cascaded all fiber pulsed arrangement for amplifying optical discrete pulses generated by an external source, comprising:
- upstream and downstream fiber amplifiers each operative to amplify the discrete pulses, a stretch of an optical path, including the upstream and downstream fiber amplifiers, being provided with internal impurities defining a parasitic resonant cavity therebetween;
- at least one passive saturable absorber (SA) located in the parasitic cavity and coupled to output and input of respective upstream and downstream fiber amplifiers, the SA being configured with a recovery time τ<Tround_trip, where τ is a recovery time of the SA, and Tround trip is a round-trip time of light within the resonant cavity, the τ being selected to have Qsat_sa<Qsat_gb and to be sufficient to prevent emergence of self-pulsing effect in the fiber amplifiers, wherein Qsat_sa is a saturation energy of the SA and Qsat_gb is a saturation energy of fiber amplifiers.
Dependencies are inferred from the claim text.