Thermal effects in narrow linewidth single and two tone fiber lasers.

Significant effects from heating occur in both single and two tone fiber amplifiers. Single tone 1064 nm amplifiers have highest efficiency when the external environment surrounding the gain fiber is cold while 1064 nm two tone amplifiers co-seeded with broadband 1040 nm have maximum efficiency when the gain fiber is hot. It is shown experimentally that changes in the temperature of the core of the gain fiber have dramatic effects on the 1064 nm/1040 nm power distribution in the output of two tone amplifiers.

Enhancement of output power from narrow linewidth amplifiers via two-tone effect--high power experimental results.

Two-tone 1064 nm fiber amplifiers having both cold (16°C) and pump induced temperature zones co-seeded with narrow linewidth 1064 nm and broad linewidth 1040 nm photons have been shown to have a power enhancement factor between 1.6 and 1.8 relative to the optimum single-tone 1064 nm amplifier while maintaining an efficiency of 65% or greater.

Theory of electronically phased coherent beam combination without a reference beam.

The first theory for two novel coherent beam combination architectures that are the first electronic beam combination architectures that completely eliminate the need for a separate reference beam are presented. Detailed theoretical models are developed and presented for the first time.