提出一种相干激光聚焦式传输进行相干合成的方法。通过液晶相控阵波束方向控制技术, 可以在目标区域内的任意位置进行相干合成。基于实际参数, 建立相干合成理论模型, 在此模型下5束相干激光在距离为100 m、坐标为2 m的位置进行相干合成后, 激光的峰值光强增加到单束激光的16.9倍。研究了目标区域内不同位置的峰值光强变化规律, 分析发现光束抖动的直接原因是出射激光的相位面产生畸变, 深层原因是电压量化引起的相位延迟误差。量化位数小于16时, 增加量化位数可以显著减小位置误差, 提高峰值光强；量化位数大于16时, 量化位数不再是位置误差的主要原因。传播距离大于5000 m时聚焦式相干合成可等效为平行式相干合成, N束激光合成后峰值光强接近单束激光的N2倍。

An approach to focused coherent beam combining (CBC) is proposed. Based on the beam steering technology by liquid crystal optical phased array (LCOPA), a combined beam can be obtained in an arbitrary position within the target region. A theory model of CBC is built based on practical parameters. When 5 coherent beams are combined in position with 100 m distance and 2 m coordinate, the value of peak intensity increases to 16.9 times. Trends of peak intensity in the target region are researched. Analysis indicates that the direct reason for beam jitter is the distortion of the phase front, and the deeper reason is the error of the phase delay caused by voltage quantization. When the quantization bit is less than 16, the position error decreases and the peak intensity increases as the quantization bit increases. However, when the quantization bit is greater than 16, the quantization bit is not the main reason any more. As the transmission distance is larger than 5000 m, the focused CBC is equivalent to the parallel CBC. The peak intensity increases to N2 times when the number of coherent beams is N. Research results can lay a foundation of the application of LCOPA in CBC.