A Fast Wavelength-Swept kHz-Linewidth Laser for Multi-kW Fiber Amplifiers

AdValue Photonics proposes to develop a novel modulation technique for a narrow-linewidth seed laser for mitigation of optical nonlinearities in multi-kW high power fiber amplifier systems. The novel modulation technique allows us keeping as narrow as kHz-level operation of instantaneous laser linewidth in multi-kW high-power fiber amplifiers without the onset of detrimental SBS - stimulated Brillouin scattering effect. Optical path differences between different fiber amplifier channels in a coherent beam combining system can easily be synchronized to the modulation of the proposed seed laser, thereby yielding a robust phase locking scheme between output laser beams from different fiber amplifier channels. In the Phase I program, we will demonstrate the feasibility of the proposed new approach. In Phase II program, we will demonstrate and build a prototype seed laser unit and test it in Lockheed Martin/AcuLight multi-kW high-power fiber amplifiers. Approved for Public Release | 18-MDA-9817 (23 Oct 18)