ABSTRACT
We demonstrate coherent beam combining using a two-dimensionally patterned diffractive optic combining element. Fifteen Yb-doped fiber amplifier beams arranged in a 3×5 array were combined into a single 600 W, M²=1.1 output beam with 68% combining efficiency. Combining losses under thermally stable conditions at 485 W were found to be dominated by spatial mode-mismatch between the free space input beams, in quantitative agreement with calculations using the measured amplitude and phase profiles of the input beams.
ABSTRACT
Four actively phase-locked beams produced by fiber amplifiers in a master oscillator power amplifier (MOPA) configuration were coherently combined in a glass capillary re-imaging waveguide producing more than 100 W of coherent output with 80% combining efficiency and excellent beam quality. The beam combiner components maintained a temperature below 30 degrees C with no external cooling at >100 W of combined power.
Subject(s)
Fiber Optic Technology/instrumentation , Fiber Optic Technology/methods , Lasers , Light , Optical Fibers , Equipment Design , Hot Temperature , PolymersABSTRACT
A novel, highly accurate, all electronic technique for phase locking arrays of optical fibers is demonstrated. We report the first demonstration of the only electronic phase locking technique that doesn't require a reference beam. The measured phase error is lambda/20. Excellent phase locking has been demonstrated for fiber amplifier arrays.
