Dammann-grating-based passive phase locking by an all-optical feedback loop.
A Dammann grating is used as a spatial filter for a passive coherent beam combination (CBC) of three Yb-doped fiber amplifiers with an all-optical feedback loop. Using this diffractive-optics-based spatial filtering technique, we demonstrate CBC with 20 W output power, and the visibility of the far-field interference pattern is up to 88.7%. Measurements suggest that this approach is robust with respect to laboratory environment perturbations, and it can scale to high powers and large arrays.
Yifeng
Y
Yang
Houkang
H
Liu
Ye
Y
Zheng
Man
M
Hu
Chi
C
Liu
Yunfeng
Y
Qi
Bing
B
He
Jun
J
Zhou
Yunrong
Y
Wei
Qihong
Q
Lou