EXPANDING BEAM LASER AMPLIFIER AS A COST EFFECTIVE ARCHITECTURE FOR ASAT

THE EXPANDING BEAM LASER (EBL) AMPLIFIER CONCEPT IS PRESENTED AS A METHOD FOR EFFICIENT SCALING OF VARIOUS LASERS TO THE HIGH AVERAGE POWER LEVELS REQUIRED FOR ASAT APPLICATIONS. THE EBL AMPLIFIER CONCEPT INCREASES THE STAGE GAIN WHICH CAN BE EFFICIENTLY OBTAINED FROM A POWER AMPLIFIER BY FACTOS OF 10-30 SO THAT INTERMEDIATE AMPLIFIERS CAN BE ELIMINATED IN THE MOPA CHAIN. SUCH SIMPLIFICATION OF THE SYSTEM ARCHITECTURE RESULTS IN A SIGNIFICANT COST SAVINGS AND INCREASED RELIABILITY. ADDITIONAL ADVANTAGES INCLUDE REDUCE BEAM QUALITY SENSITIVITY TO LASER MEDIUM INHOMOGENEITIES, A SIMPLIFIED OPTICAL SYSTEM AND REDUCED LEVELS OF AMPLIFIED SPONTANEOUS EMISSION. TO ILLUSTRATE THE ADVANTAGES OF THIS ARCHIETECTURE, SRL HAS INVESTIGATED THE BENEFITS OF THE EBL FOR LARGE GROUND BASED RARE GAS HALIDE LASERS AND SMALLER CO2 LASERS. THE ADVANTAGES OF THE EBL AMPLIFIER LEAD TO A REDUCTION IN COST FOR HIGH AVERAGE POWER RARE GAS HALIDE LASER SYSTEMS OF A FACTOR OF 3 AND HAVE THE POTENTIAL TO MAKE THESE LASERS COST COMPETITIVE WITH OTHER GROUND BASED LASER (GBL) ASAT APPROACHES. IN PHASE I A DETAILED PROOF-OF-PRINCIPAL EXPERIMENT WILL BE DESIGNED. THE DESIGN WILL BE ACCOMPLISHED BY OBTAINING DATA OF THE RELEVANT LASER PARAMETERS ON AN EXISTING EXCIMER LASER FACILITY DURING PHASE I. THE EXPANDING BEAM AMPLIFIER WILL BE EXPERIMENTALLY VERIFIED IN PHASE II OF THIS SBIR.