Method and apparatus for controllably de-energizing amplifier in high power narrow linewidth fiber laser systems

Abstract

A high power narrow linewidth laser system is provided with a master oscillator power fiber amplifier (MOPFA) architecture which includes a master oscillator (MO) and booster. The laser system includes at least one photodetector (PD) operative to detect pulsed stimulated Brillouin scattered (SBS) light propagating backwards from the PA to the MO. The PD converts the detected SBS light to an electrical signal which corresponds to a pulse peak power of the detected SBS light. The laser system has a central processing unit (CPU) receiving the electrical signal and operable to determine if the peak power of the detected SBS light is within a threshold safety power range of the SBS light which ranges between 8 and 12 kW. If the peak power is within the threshold safety range, the CPU controllably decreases an output power of MO-generated signal light within a 50-500 ns time period prior to the shutdown of the booster so as to prevent the determined SBS peak power from reaching a critical peak power in a 1-5 MW.

Dependencies are inferred from the claim text.