Heterogeneous hierarchical control with delay-calibration demodulation for high-bandwidth multi-dither coherent beam combining

Abstract

The operational bandwidth of multi-dither coherent beam combining (CBC) systems is fundamentally constrained by hardware-induced phase misalignment. We theoretically reveal that this misalignment scales the error signal by a cosine factor of the phase lag, thereby degrading loop gain. To break through this bottleneck, we propose a heterogeneous hierarchical control architecture that employs a bisection-based phase-boundary searching strategy to achieve automated delay-calibration demodulation. With sub-1° calibration accuracy attained in 2.4 s, the system achieves superior dynamic performance, as experimentally demonstrated by a 12.2 μs recovery time under step disturbances and a 10 kHz closed-loop bandwidth under sinusoidal perturbations. This architecture provides a hardware-efficient and high-bandwidth solution for multi-dither CBC systems.