Share Email Print
cover

Proceedings Paper

Multi-kW coherent combining of fiber lasers seeded with pseudo random phase modulated light
Author(s): Angel Flores; Thomas Ehrehreich; Roger Holten; Brian Anderson; Iyad Dajani
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

We report efficient coherent beam combining of five kilowatt-class fiber amplifiers with a diffractive optical element (DOE). Based on a master oscillator power amplifier (MOPA) configuration, the amplifiers were seeded with pseudo random phase modulated light. Each non-polarization maintaining fiber amplifier was optically path length matched and provides approximately 1.2 kW of near diffraction-limited output power (measured M2<1.1). Consequently, a low power sample of each laser was utilized for active linear polarization control. A low power sample of the combined beam after the DOE provided an error signal for active phase locking which was performed via Locking of Optical Coherence by Single-Detector Electronic-Frequency Tagging (LOCSET). After phase stabilization, the beams were coherently combined via the 1x5 DOE. A total combined output power of 4.9 kW was achieved with 82% combining efficiency and excellent beam quality (M2<1.1). The intrinsic DOE splitter loss was 5%. Similarly, losses due in part to non-ideal polarization, ASE content, uncorrelated wavefront errors, and misalignment errors contributed to the efficiency reduction.

Paper Details

Date Published: 11 March 2016
PDF: 6 pages
Proc. SPIE 9728, Fiber Lasers XIII: Technology, Systems, and Applications, 97281Y (11 March 2016); doi: 10.1117/12.2213423
Show Author Affiliations
Angel Flores, Air Force Research Lab. (United States)
Thomas Ehrehreich, Air Force Research Lab. (United States)
Roger Holten, Air Force Research Lab. (United States)
Brian Anderson, Air Force Research Lab. (United States)
Iyad Dajani, Air Force Research Lab. (United States)


Published in SPIE Proceedings Vol. 9728:
Fiber Lasers XIII: Technology, Systems, and Applications
John Ballato, Editor(s)

© SPIE. Terms of Use
Back to Top