Patent ID: 9106051
Filing Date: 2015-08-11
Classification: H01S

Abstract:
1. A seed beam source for a fiber amplifier system, said seed beam source producing a seed beam having reduced thermal instability caused by coupling of seed beam light propagating through an optical fiber into higher order modes, said optical fiber having a fiber core, said seed beam source comprising: a plurality of M continuous wave master oscillator lasers, each generating a laser beam at a different wavelength; a plurality of M switching modulators each receiving the laser beam from a particular one of the master oscillator lasers, each switching modulator being controlled so as to output its laser beam as optical pulses based on a predetermined timing sequence, wherein the plurality of M switching modulators are also controlled so that the optical pulses have a pulse width that is less than or equal to 1/M times a thermal diffusion time across the fiber core so as to provide the reduced thermal instability; an optical coupler responsive to the optical pulses from the plurality of switching modulators where the optical coupler only receives one of the optical pulses from the switching modulators at any particular point in time, and where the optical coupler continuously receives the optical pulses from the plurality of switching modulators and outputs an interleaved continuous optical seed beam including the optical pulses from all of the switching modulators; and an electrical pulse driver selectively providing an electrical signal to the plurality of switching modulators so as to cause the switching modulators to only output one of the optical pulses at the particular point in time.