In:
Applied Optics, Optica Publishing Group, Vol. 61, No. 34 ( 2022-12-01), p. 10222-
Abstract:
Coherent beam combining (CBC) of a fiber laser can scale the output power while
maintaining high beam quality. However, phase detection and control remain a challenge for a high-power CBC system with a massive laser
array. This paper provides a novel, to the best of our knowledge, cascaded phase-control technique based on internal phase detection and
control, called the cascaded internal phase-control technique. The principle of the technique was introduced in detail, and the numerical
simulations were carried out based on the stochastic parallel gradient descent (SPGD) algorithm. The results indicated that the cascaded
internal phase-control technique was compatible with the massive laser array. Compared with the traditional CBC based on the SPGD algorithm,
the control bandwidth could be improved effectively about seven times (120 steps) than the traditional SPGD algorithm
(830 steps). Furthermore, the average root mean square of residual phase error was decreased to 0.03 rad ( ∼ λ / 209 ) with a laser array of 259 channels ( 7 ∗ 37 ), which was 0.36 rad ( ∼ λ / 17 ) in the traditional SPGD algorithm.
In addition, the element expanding capacity was analyzed. Since there is no large-aperture optical device in the phase-detection system,
this technique has the advantage of freely designing the caliber of the laser emitting system. This paper could offer a
reference for the high-power massive laser array system design and phase control.
Type of Medium:
Online Resource
ISSN:
1559-128X
,
2155-3165
Language:
English
Publisher:
Optica Publishing Group
Publication Date:
2022
detail.hit.zdb_id:
207387-0
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