PCF Based High Reliability Arbitrary Pulse pattern Laser Amplifier

Optical Engines Inc will develop a hybrid Master Oscillator Power Amplifier (MOPA), system counter pumped PCF amplifier for the highest pulse energy available from a fiber laser system. This all fiber front end will be coupled to a small bulk amplifier with the ultimate goal of increasing the energy of the fiber portion of the system such that the bulk portion will not be necessary. This arbitrary pulse generation, all fiber amplifier will be highly reliable through the complete removal of all free space optics resulting in a device that is significantly more robust and reliable. For nearly 4 years, Optical Engines has worked in close collaboration with Fermi National Laboratory providing fiber expertise and PCF power amplifiers for their particle beam notching development work. This arbitrary pulse pattern laser amplifier system will utilize Optical Engines Patented Etched Air Taper fiber pump combiner technology. This technology has been utilized in directed energy systems with pump efficiencies of over 99% and signal efficiencies of over 96% have been demonstrated in commercially available co pumped devices; reliably operating at over 2.5kW of pump power for over 5 years. Optical Engines will utilize a double pass amplifier modulation stage with phase modulation in order to create both the arbitrary pulse patterns as well at the necessary spectral spreading to increase non-linear thresholds. This pulse forming seed stage will be followed by 2 mid stage amplifiers based on advanced LMA amplifier designs to boost the signal to necessary for power amplification. Key to this program would be to increase the pulse energies achievable in fiber amplifiers to minimize the requirements for any following bulk stage. Bulk amplifier stages are system limiters for achieving high average power so it is important to have a fiber power amplifier that can supply the highest energies possible. In order to achieve this superior performance, counter pumped architectures, composite amplifier designs and UV co pumping will also be investigated. In order to test these amplifiers, Optical Engines will continue its close collaboration with FNL to develop the appropriate testing structures to create realistic test scenarios. Optical Engines has developed pulsed amplifiers to over 300W and CW narrow line width systems to 2kW going to over 5kW of near diffraction limited power output. For this program Optical Engines will also work to develop architectures that can be extended to multi-kW operation within the next 2-5 years.